23425541 COMPLETE Project on Networking
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SWAMI PARMANAND COLLEGE OF ENGINEERING & TECHNOLOGY SIX MONTHS INDUSTRIAL TRAINING REPORT ON
NETWORKING (MCSE & CCNA) AT
JETKING SEC 34 , CHANDIGARH SUBMITTED AS A PART OF COURSE CURRICULUM
BACHELOR OF TECHNOLOGY IN
ELECTRONICS & COMMUNICATION ENGINEERING Under the Guidance of Mr. Baljit singh Mr. Inder Gulati Submitted To: Er. Harpreet Kaur (HOD)
Submitted By: Saroj Dogra
DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING SWAMI PAMANAND COLLEGE OF ENGINEERING & TECHNOLOGY, DERA BASSI, MOHALI
I feel deeply indedted to Mr. Baljit Singh, Microsoft trainer who delivered valuable lesson on MCSE, his indepth knowledge about the subject helped me understand the subject in better way. His method of teaching the minute details helped me a lot to acquire the insight into the subject. I am also grateful to Mr. Inder Gulati, CCNA trainer for giving best knowledge about CCNA.the way he instilled knowledge of the subject was undoubtly praise worthy and valuable. I am also thankful to Jetking institution as a whole that is doing yeoman’s service by teaching the learner avreast with the computer , networking and hardware knowledge that is the need of the day. I will be failing in my duty if I do not acknowledge my husband Mr. Nardev Singh Rana who always stood by my side during my studies. I am indepted to my son’s Anirudh Rana and Romil Rana who never clamed my time and get bore by my long absence rather silent. Last but not the least, I thank all my classmates at Jetking for extending kind co-operation.
List of Figures
Name of Figure
Local Area Nework
Campus Area Network
Metropolitan Area Network
To find location of a computer using FQDN
Structure of domain forest and domain tree
Parent child relationship model
Direct Sharing Scenario
Scenario of win proxy server
Architecture of router
Variable Subnet Mask
Scenario of Telnet
Scenario of Static Routing
Routing table of covered networks
VLAN Operation 105
IEEE 802.11 Standard
List of tables
Name of table
Difference between Workgroup & Domain
Comparison between IPv4 and IPv6
Category and Speed of UTP cables
Colour Coding for straight Cable
Colour Coding for Crossover cable
Colour Coding for Rollover Cable
Difference between Workgroup and Domain
Exchange Server with different operating systems
Router interfaces and connectors
Default address mask in binary & dotted decimals
Decimal and Binary values of subnet mask
Subnet mask, valid hosts, broadcast address
Difference between RIPV1 & RIPV2
Difference between IGRP and RIP
INTRODUCTION Company Profile LITERATURE RIEVIEW NETWORKING
1.1 2 3 3.1
3.1.1 Models of Networking
3.1.2 Categories of network
3.2.2 MAC Addressing
NETWORKING MEDIA Ethernet Cabling
3.4 OPERATING SYSTEM 3.4.1 Types of Operating Systems DNS SERVER 3.5.1
PARTS OF DNS SYSTEM
3.5.2 DNS Zone 3.6 DHCP SERVER
1 1 5 6
Introduction to networking
3.2 IP ADDRESSES and MAC Addresses
15 17 20 20 22 23 26 28
3.6.1 Working of DHCP Server
3.8.1 Direct Sharing
3.8.2 ICS (Internet Connection Sharing)
3.8.3 Win Proxy Server
3.8.4 NAT (Network Address Translation)
3.9 VIRTUAL PRIVATE NETWORK (VPN) 3.9.1
Types of VPN
3.10 ROUTING 3.10.1
51 Types of Routing
3.11 EXCHANGE SERVER
3.11.1 Elements of Exchange Server
Requirements for Exchange Server
3.12 Open System Interconnection (OSI) Model 3.12.1 Description of Different Layers 3.13 ROUTERS
57 58 60
3.13.1 Router Architecture and its Key Component
3.13.2 Router Interfaces & Ports 3.13.3 Modes of Router
3.13.4 Configuring Password
3.13.5 Managing Configuration
Advantages of subnetting
3.14.2 Types of Subnetting 3.15 TELNET
70 70 73 75
3.15.1 To Access the Device Remotely
3.15.2 Commands to assign IP addresses to the interfaces 76 3.16 ROUTING
3.16.1 TYPES OF ROUTING
3.16.2 Routing Protocol Basics
3.1.3 R IP (Routing Information Protocol)
IGRP ( Interior Gateway Protocol)
3.1.5 EIGRP(Enhanced Interior Routing Protocol)
3.1.6 OSPF (Open Shortest Path First)
3.17 LAN SWITCHING
VLAN (Virtual LAN)
Vlan Trunking Protocol (VTP)
Wi-Fi (WIRELESS FIDELITY)
3.18.1 Wireless LAN
3.18.2 Wireless Standards
1. INTRODUCTION This project report pertains to six months industrial training that I had underwent at JETKING, Chandigarh as part of curriculum of degree in Bachelor of technology in Electronics and Communication engineering as required by Swami Parmanand College of engineering and technology (affiliated to Punjab Technical University, Jalandhar) . I learnt a lot from professional managers and skilled engineers. I had a great learning experience as trainee in this firm. I learnt a lot about how different networks are controlled in the industry or any department with the help of networking processes, under MCSE and CCNA. I have learnt about different type of servers like DHCP Server, DNS Server, NAT Server. Also I have learnt how to control the LAN and MAN networks under MCSE (Microsoft Certified System Engineers) and how to control MAN and WAN networks under CCNA (CISCO Certified System Engineers). Justification cannot be done to whatever I have learnt in these six months within a few pages but I have still tried my best to cover as much as possible in this report. In this report I have tried to sum up the technical knowledge I have gained in my six months of training.
Company Profile Jetking is an organization came into establishment in1947. Jetking is India’s
number one Computer Hardware and Networking Institute.
Birth and Evolution It took a lot of failure before mankind tasted technological success. Jetking evolved in tune with the changing face of technology. During 55 years in the field of electronic technology. Jetking successfully trained thousands of students to overcome failure for high paying careers.
Pioneered “Do-It-Yourself Kits” in India
Introduced Asia- 72, Fairchild and Wildcat transistors
Became a Public Limited Company and also introduced entertainment electronics product-T.V sets, Two-in-ones and amplifiers.
Launched Jetking School of Electronics Technology
Network of Jetking training centers spread all over India
Opening of Jetking, Chandigarh
Tie-up with Heath kit Educational System (U.S.A.)
Introduced advanced courses on Pentium, Notebooks, Modems, Email/Internet, LAN 4.X
Novell Education Academic Partner
Representative for International Correspondence School (ICS), USA in India
Added cyber technology to the curriculum
ISO 9001-2000 company and Authorized Microsoft online testing centre (VUE) for MS, CISCO, MCSA, MCSE, CCNA, A+ etc.
Mr. Suresh G. Bharwani is the CHAIRMAN and MANAGING Director of Jetking Infotrain Ltd. India’s leading Computer Hardware and Networking Institute. With the vision to promote and the conviction to deliver the widespread propagation of computer hardware and networking education across the nation, Mr. Bharwani was the first to set up an training institute offering innovative courses in computer hardware in 1990. Jetking’s core competency lies in providing complete training and developing hardware engineers and professionals with sound technical knowledge. It focuses on the overall development of personality of an individual with emphasis on personality development, presentation and communication skills, leadership skills etc. Jetking has established more than 125 operational centers and 250 faculties across the country and has trained over 3,50,000 students who have move onto the crave
success- full career. With its alumni placed in the best of organizations in India and some abroad, Jetking,s vocational training and placement promises has helped build the career prospects of many young boys and girls. The company has been awarded the ISO 9000:2000 certification in 2003.The company has been awarded the “ Maharashtra IT Award” for a key role in manpower activities in year 2006-07,it was felicitated with Franchise Award as Best Franchisor for the year 2007-08.Also,ranked 4th in the list of 26th hot franchises as per outlook money magazine. Mr. Suresh Bharwani was awarded with “Pike’s Peak Award” by the Bob Pike Group USA for effective implementing smart lab plus for making technical training fun, faster and easier for non- technical person. Across all the sectors, industries are upgrading their information technology system. Industries ranging from plastics, chemicals, textiles and power to the automotive and telecom sector are now IT savy. Government and public sectors are going hi-tech with EDI and computer networks. The IT industry, software companies, data centers, ITenabled services providers are all equipped with advance IT system and networks. The increasing number of call centers, BPO’s etc., have given a further boost to the hardware and networking industry. The courses in jetking comprises lecture and theory session, with a great focus on active participation through smart lab plus ,that focuses on audio visual and learning with hands-on training and equips students with an in depth domain knowledge that is technical; it also equips students with soft skills ,to face the multi-faceted challenges of corporate world. PLACEMENT: Jetking is the first and only institute that promises the 100% jobs guarantee to its students. The companies that have recruited jetkings students include: Samsung, Sun Micro system, IBM, Canon, Siement, reliance, TATA, Compaq HP invent, IT-T solutions, Videsh Sanchar Nigam Limited, D-Link, Novell, Dell, Wipro, LG, ICIC Infotech and several other MNCs.
Any student who has qualified his or her HSC/SSC examination is eligible to take up a course at jetking. The one year program Jetking certified hardware and networking professionals give 680 hours of in-depth knowledge to a student in Basic electronics and computer applications. Computer hardware and peripherals, window 2003 administrator and network administrator (soon it will be replaced with window server 2008).Apart frame technical knowledge there are personality development sessions which groom the student’s personality, their ability to perform better. Jetking, India’s leading hardware and networking training institute has trained over 3,00,000 students from its 125 centers spread across India. With its alumni placed in the best of organizations in India and some abroad, Jetking vocational training and placement promises has helped build the career prospects of many young boys and girls. Jetking has partnered with some of the worlds most renowed names in networking to provide you with cutting edge courses and technologies. With academic partnerships with Microsoft, Comp TIA,LINUX, NOVELL, and person VUE . Jetking Chandigarh is a division of Hi-Tech point. Hi-Tech point is an ISO 90012000 IT company. It was established in year 1993 and run by a company of IT professionals. Jetking Chandigarh branch is considered to be the best centre among all centers. It has bagged number 1 center award consecutively for last 7 years. Here training on various fields is going on like Basic Electronic, Hardware, Networking, JCHNP Analog and Digital electronics and Hardware, RHCE, RHCSS, MNA, MCSE (Microsoft System Engineers), MCITP, MNA, CCNA (CISCO Certified Network Associate), CCNP(CISCO Certified Network Professional). Partnership with industry leaders like Microsoft and Red Hat Jetking ensure its students authentic courseware and technology.
Computer Networking is a very vast project in the present developing era of electronics and communication. Now a days, computers are used in a wider range. All the organizations are using multiple computers within their departments to perform their day to day work. Computer network allows the user to share data , share folders and files with other users connected in a network. Computer Networking has bound the world in a very small area with it wide networking processes like LAN, MAN, WAN. The courses in jetking comprises lecture and theory session, with a great focus on active participation through smart lab plus ,that focuses on audio visual and learning with hands-on training and equips students with an in depth domain knowledge that is technical; it also equips students with soft skills ,to face the multi-faceted challenges of corporate world.
3. NETWORKING 3.1
Introduction to networking Networking is a practice of linking of two or more computing devices such as
PCs, printers, faxes etc., with each other Connection between two devices is through physical media or logical media to share information, data and resources. Networks are made with the hardware and software.
Fig 1: computer network
3.1.1 Models of Networking Model means the connectivity of two computers. We have many types of networking models. (i)
Client – Server Model
Peer to Peer Model (Workgroup Model)
Client –Server Model In a Client server model we have one server and many clients. A Client can share
the resources of server, but a server cannot share the resources on clients. On the point of view of administrator it’s very easy to control the network because we combine with the server also at security point of view. It is very useful because it uses user level security in which users have to remember only one password to share the resources. (ii) Peer to Peer Model (Workgroup Model) In Peer to Peer networking model all computers are in equal status, that is we cannot manage centralization, administration secutity. In Peer to Perr networking client use operating system like Window 98, Window XP, Window 2000, Window Vista. (iii) Domain Model It is a mixture of client server and peer-to-peer model. In this clients can share their resources as peer-to-peer but with the permission of the server as in client server model therefore it is commonly used model because in this security is more as we can put restriction on both server and clients.
Difference between Workgroup & Domain Table 1 Workgroup
1. It is a peer to peer networking model.
1. It is a server based networking model.
2. There is no client and no server. All the 2. There is a centralized dedicated server computers are in equal status.
computer called domain controller which
controls all other computers called clients. 3. This model is recommended for small 3. This model is recommended for large networks, upto 10 computers.
4. There is no centralized administrated 4. There is centralized administration and separately.
each PC can be administrated and managed from the server.
5. In this model, low grade OS like 5. in this model high grade OS like WIN 2000/XP professional, WIN 98 etc. can be 2000/2003 Server can be used. used. 6. Users accounts are created in each PC 6. Users accounts are created on the server and are called as Local Users.
side and are called Domain Users.
3.1.2 Categories of network Networks can be categorized as per geographical area to be covered by the network. Computer network are divided into four categories includes: Local Area Network (LAN), Campus Area Network (CAN), Metropolitan Area Network (MAN) and Wide Area Network (WAN). 220.127.116.11
Local Area Network (LAN) LAN is a computer network that is used to connect computers and work station to share data and resources such as printers or faxes. LAN is restricted to a small area such as home, office or college. Devices used in LAN are : HUB and switch. Media for LAN is UTP cables. Figure 1.2 shows how all work stations, server and printer are interconnected with the help of the network device.
Fig 2: Local Area Network Types of LAN In LANs, data can be transferred using techniques like token passing. As per techniques used for data sharing, LANS are classified into Ethernet, Token Bus, Token Ring and Fiber Distributed Data Interface (FDDI).Figure 3.3 shows LAN classification.
Fig 3: LAN classification
Advantages of LAN a). Provides communication in smaller networks, easy to install and configure. b). many users can share data or network elements at the same time which results in fast work. Disadvantages of LAN a). limited number of computers are connected in a LAN. b). LAN cannot cover large area. c). Network performance degrades as the number of users exceeds.
18.104.22.168 Campus Area Network (CAN) Campus Area Network is a computer network made up of two or more LANs within a limited area. It can cover many buildings in an area. The main feature of CAN is that all of the computers which are connected together have some relationship to each other e.g. different buildings in a campus can be connected using different CAN. It will help to interconnect academic departments, library and computer laboratories. CAN is larger than LAN but smaller than WAN. Figure 3.4 shows a CAN network.
Fig 4: Campus Area Network Devices used in CAN are : HUB, Switch, Layer-3 switch, Access Point .And the media used for CAN is Unshielded twisted pair of cables and Fiber Optics Cable.
Metropolitan Area Network (MAN)
MAN is the interconnection of networks in a city. MAN is not owned by a single organization. It act as a high speed network to allow sharing resources with in a city. MAN can also be formed by connecting remote LANs through telephone lines or radio links. MAN supports data and voice transmission. The best example of MAN is cable T.V network in a city.
Fig 5 : Metropolitan Area Network
Wide Area Network (WAN) WAN covers a wide geographical area which include multiple computers or
LANs. It connects computer networks through public networks like, telephone system, microwave, satellite link or leased line. Most of the WANs use leased lines for internet access as they provide faster data transfer. WAN helps an organization to establish network between all its departments and offices located in the same or different cities. It also enables communication between the organization and rest world. Devices used in WAN is only Router
3.2 IP ADDRESSES and MAC Addresses It is also called as logical addresses. IP is a 32 bit long and it is divided into 4 octets and dot (.) is used to separate one octet from another. It is represented in the form of decimals. There are two versions of IP addresses: -
IPv6 Table 2
Comparison between IPv4 and IPv6
It is 32 bit long.
It is 128 bit long.
It is divided into 4 octets.
It is divided into 16 octets.
Ipv4 performs broadcasting,
multicasting and unicasting.
IPv4 is divided into 5 classes:
multicasting and unicasting.
A to E.
Ipv6 doesn’t support classes.
IPv4 is in decimal form.
IPv6 is in hexadecimal form.
3.2.1 IP Address Classes IP address is a 32 bit address. It is divided into various classes namely Class A, Class B, Class C, Class D and Class E. TCP/IP defines Class D for experimental purpose. TCP /IP address contains two addresses embedded within one IP address; Network address and host address as shown in figure 3.1
ADDRESS 0 bits
Class A consists of 8-bit network ID and 24-bit host ID. Class B consists of 16bit network ID and 16-bit of host ID. And Class C consists of 24-bit of network ID and 8-bit of host ID. Address Classes Table 3: Address Classes Addres
Range of First Mask Value
Class A 0
128 to 191
192 to 223
Class D 1110
224 to 239
Reserved for multicasting
240 to 255
22.214.171.124 How to Assign IP Address to Computer An IP address assigned to a computer may either be permanent address or address that is assigned to a computer on a time lease or for temporary basis. Hence, the address granted to computers is divided into two categories Dynamic IP addresses and Static addresses. Dynamic IP Addresses Dynamic IP addresses are assigned to the devices that require temporary connectivity to the network or non-permanent devices such as portable computer. The most common protocol used for assigning Dynamic IP address is DHCP also called
Dynamic Host Configuration Protocol. The DHCP grants IP address to the computer on lease basis. Static IP Addresses Static IP addresses are assigned to the device on the network whose existence in the network remains for a longer duration. These static IP addresses are semi-permanent IP addresses which remain allocated to a specific device for longer time e.g. Server.
126.96.36.199 How to Configure IP Address in window 2003 •
Right click on My Network Places- properties
right click on working LAN card- properties
select internet protocol (TCP/IP) -properties
Tick on- Use the following IP addresses - now fill the IP address e.g 10.0.0.1
Tick on –Use the following DNS server address
Fill the preferred DNS server – 10.0.0.1
Now check the connectivity of computer with itself with command Start-run-cmd-ping 10.0.0.1
3.2.2 MAC Addressing MAC address is a hardware address that is embedded in the NIC card. It is also known as hardware address or physical address. Every NIC card has a unique MAC address assigned by IEEE. MAC address is used to identify the nodes at lower levels of OSI model. The MAC address operates at the data link layer of the OSI model. MAC address is a 12 digit hexadecimal number (48 bit address). It is made up of numbers from 0-9 or a letter from A-F. MAC address can be written in any one of the formats: ►
T o identify the MAC address in window: •
Click Start →Run
Enter cmd in the Open text book
Type ipconfig /all
The 12 digit MAC address will be shown as say 00:11:11:EA:8D:F6
To do networking we need to use some type of media. There are many types of media. (i)
Fiber optic cable
Twisted Pair of Cables
Coaxial Cable Coaxial cable consists of an insulated copper conductor surrounded by a tube shaped copper braid outer copper tune and the inner conductor have the same axis of curvature hence it called coaxial cable. It is basically of two types: (i)
Base Band Cable (RG – 59)
Broad Band Cable (RG – 58)
We used Base Band signal cable in Networking of Computers, It is so called because it carries single frequency. Its speed is 10 Mbps and impedance is 50 Ω. Where as Broad
Band Cables carries multiple frequencies. Connector used for Coaxial cable is BNC(British Novel Connector) connector. ARCnet uses RG-62 coaxial cable. It has an impedance of 93 Ω and has a comparatively lesser attenuation, hence yield greater distances. These cables are expensive and provide high propagation factor.
Fiber Optical Cable Fiber optic cable consists of a very fine fiber made from two types of glass, one for the inner core and the other for the outer layer. Here signal is transmitted in the form of light. Different varieties of fiber optics is used depending on the size of the network. Single mode fiber optics is used for networks spanning longer distance. Fiber Optics has lower propagation factor than coaxial cable. It is a costly but more secure transmission media. Twisted Pair Cable There are two wires, which are twisted with each other to avoid EMI (Electro Magnetic Induction).these cables are easy to terminate. However they have a slightly higher value of attenuation value and hence have limited distance covering capacity. Connector used for Twisted Pair of Cable is (Registered Jack) RJ-45 and RJ-11. There are two types of twisted pair of cables: •
STP (Shielded Twisted Pair): In this an extra wire which is called shielded wire is wrapped over the inner
cover which holds copper in pairs. This protection is used to protect signal from external noise. •
UTP (Unshielded Twisted Pair) In this type of wire no shielded cover is there for extra protection from noise. There are different categories of UTP cables:
Categories of UTP Cables Table 4: Category and Speed of UTP cables
56 Kbps 4 Mbps
CAT-2 CAT-3 CAT-4 CAT-5
10 Mbps 16-20 Mbps 100 Mbps
There are three types of Ethernet cables: •
188.8.131.52 Straight cable It is used when we have to connect •
PC TO Switch
PC to Hub
Hub to Router
Switch to Router
Colour Coding for straight Cable TABLE 5
184.108.40.206 Crossover Cable It is used when we have to connect: •
PC to PC
Hub to Hub
Switch to switch
Router to Router
PC to Router
Hub to Switch
Colour Coding for Crossover cable Table 6 Colour Coding for Crossover cable
220.127.116.11 Rollover Cable Rollover cable isn’t used to connect any Ethernet connections together, but Rollover cable can be used to connect a host to a router console serial communication (com) port. NOTE: Straight cable and Cross cables are used for data transfer but Rollover cables are not used for data transfer. There are two methods for manufacturing Rollover cables:
Table 7 Colour Coding for Rollover Cable
568A (one end)
568B (other end)
3.4 OPERATING SYSTEM 3.4.1 Types of Operating Systems (i) DOS (Desktop Operating System)
(ii) NOS (Network Operating System)
Table 8: Operating Systems DOS
1. It is a desktop operating system.
1. It is a network operating system.
2. It is used in small networks.
2. It is used for large networks.
3. In this OS, there is less security.
3. In this OS, there is more security.
4. In this OS, all computers are clients.
4. In this OS, there are servers and
5. In this OS, MS-DOS, GUI package clients. Win 3.1, Win 95, Win 98, Win ME comes.
5. In this OS Win NT, Win 2000, Win 2003, LINUX, UNIX, Novell and MAC comes.
18.104.22.168 Introduction to Window 2003 Server
Window server 2003 (also referred to as WIN 2k3) is a server operating system produced by Microsoft. Introduced in 24th April 2003 as the successor to window 2000 server, it is considered by Microsoft to be the corner stone of its window server system line of business server products. An update version Window Server 2003 R2 was released manufacturing on 6th dec, 2005. its successor window 2008 was released on 4th feb, 2008. According to Microsoft, window server 2003 is more scalable and deliver better performance than its predecessor window 2000. Features of Window 2003 (i)
A significant improved version of Internet Information Service (IIS)
Increased default security over previous version due to the built in firewall and having most services disabled by default.
Manage your server-a role management administrative tools that allow an administrator to choose what functionality the server should provide.
Improvement to Active Directory.
Improvement to Group Policy handling and Administration.
Provides a Backup system to restore lost files.
Improved disk management, including the ability to Backup from shadows of files, allowing the Backup of open files.
Improved security and command line tools which are part of Microsoft initiative to bring a complete command shell to the next version of window.
Support for a hard based “Watch Dog Timer”, which can restart the server if the operating system does not suspend with in a certain amount of time.
Removed Features •
The ability of creating server disk automated system recovery (ASR) is used instead .
Edition of Window 2003 Window server 2003 comes in a number of editions, each targeted towards a particular size and type of business. In general, all variant of window server 2003
have the ability to share files and printers, act as application server and host message queue, provide email services, authenticate users, act as an X.509 certificate server, provide LDAP (Light Weight Directory Access Protocol) services, serve streaming media, and to perform other server-oriented functions.
DNS SERVER DNS stands for domain name system. DNS system is a standard technology
for managing the names of websites and other internet domains. DNS techniques allows you to type names into your web browser like computer networking, about computer and allow your computer to automatically find that address on internet. DNS is the resolution mechanism used by Window Server 2003 clients to find other computers and services running on those computers for computers in a window 2003 network infrastructure to talk to one another, one of the key ingredients is the DNS server .Host name alone do not communicate globally but communicate locally, but if domain name is added along with it then the host name can communicate globally. DNS is use for name reservation i.e. to convert IP address to host name and host name to IP address or the function of DNS is to resolve host name such as www.yahoo.com to an IP address. User identify only user friendly name and all computers and technologies identify IP address and MAC address DNS is use to solve this problem because DNS is used to convert host name FQDN (fully qualified domain name) to IP address and IP address to host name .
3.5.1 PARTS OF DNS SYSTEM (i)
22.214.171.124 HOST NAME Host name is a computer name and is also called is NetBIOS (network basic Input/ output system) name. NetBIOS is actually an application layer protocol that can use the transport services of TCP/ IP when used in routed network. A NetBIOS name is 16- byte addresses that identify a NetBIOS resource on the network. 126.96.36.199 DOMAIN NAME Domain name is used to identifies the internet site one can identifies the location without having to remember the IP address of every location e.g. yahoo.com or gmail.com
188.8.131.52 FQD FQDN means fully qualified domain name which represents a hostname appended to the parent name space in hierarchy. Also in fully qualified domain name different levels of namespace are visualize as in fig below this hierarchy is visualized─ the root level namespace, top─ level domain, and so on, in use throughout the internet today. Left most portion of the FQDN is the host portion of the name. A host name is alias we give to an IP address.
Fig 6:To find location of a computer using FQDN FQDN is a unique name in the computer on the network. We can identify host id and location of a computer as in fig above. Suppose we want to find location of pc1 with IP address 184.108.40.206, which is in lab2, 2nd floor in the organization center. The FQDN for this is Pc1.row3.lab2.floor2.center.com But this address is very lengthy to locate pc1 so to simplify this we use “c name” technique as: Pc1.center.com=220.127.116.11 18.104.22.168 Domain Namespace DNS operates in what is known as DNS namespace. The DNS namespace is an organized, hierarchical division of DNS names. Domain namespace enable users to easily locate the network services and resources. The domain namespace include the root domain, the top level domain of the organization and organize these domain in a hierarchical tree structure. Namespace works on the hierarchical tree structure of root domain. There are total 13 root domain working in the internet, they are A, B, C, D, E, F, G, H, I, J, K, L and M. There is one root domain, which acts as the starting point of the
fully qualified domain names. This root domain is designated with a dot (.). Fig 6.2 shows the tree structure or domain namespace.
Fig 7: Tree structure or Domain Namespace 22.214.171.124 DNS server Any computer providing domain namespace is a DNS server. DNS server is used to convert host name FQDN into IP address and IP address into host name FQDN. To store the name-to-IP-addresses mappings so crucial to network communication, name server uses zone files.
3.5.2 DNS Zone Zone is the part of DNS database that contain record of domain or multiple domain. If the domains represents logical division of the DNS namespace, zones represents the physical separation of the DNS namespace. In other words information about records of the resources within DNS domain is stored in a zone files, and this zone files exist on hard drive of server. Zone files are divided into one of two basic types:
Forward lookup zone: Provides host-name-to-IP-address resolution
Reverse lookup zone: Provides IP-address-to-host-name resolution
Resource record stored in a zone file
Each record stored in a zone file has a specific purpose. Some of the records set the behavior of the name server, others have the job of resolving a host name or service into an IP table. (i)
NS (Name Server): These specify the name servers that are authoritative for a given portion
of DNS namespace. These records are essential when DNS servers are performing iterative queries to perform name resolution. (ii)
SOA (Start of Authority): This resource record indicates the name of origin for the zone contains the name
of the server that is the primary source for information about the zone. The information in an SOA record affect how often transfer of the zone are done between servers authoritative for the zone. It is also used to store other properties such as version information and timings that affect zone renewal or expiration. (iii)
CNAME (Canonical Name):
CNAME can be used to assign multiple names of a single IP address.
For example, the server hosting the site www.abc.com is probably not named www, but a CNAME record exist resolution of www to an IP address all the same. The CNAME record actually points not to an IP address, but to an existing A record in the zone. 126.96.36.199 Steps to Install and configure DNS server •
Start → control panel→ add and remove program
Add remove window components
Select networking services and click on detail button
Check box of DNS server
Ok and finish
188.8.131.52 Creating a Forward Lookup Zone •
Statically fill the IP address
Start →administrator tools
DNS→ right click on forward lookup zone
New zone→ next
Select primary zone→ next
Enter zone name (abc.com)→ next
Tick Allow both secure and non secure updates and secure dynamic updated
now click on created zone (abc.com)
new host→ enter host name for global level (i.e by entering www) fill IP address of the web server , click on add button
enter another host name, a blank host with same IP i.e do not fill its host name
steps to change SOA and NS records •
Right click on SOA records → properties
Fill primary server e.g (www.abc.com)→ responsible person
host master.abc.com→ apply→ ok
right click on NS records
click on add button→ enter FQDN→ www.abc.com
resolve→ ok→ apply→ ok
Now go to start menu →
On Client Side → To access DNS server fill IP address of server then use ping command e.g
Creating a Reverse Lookup Zone
Right click on reverse lookup zone
New zone→ next→ select primary zone→ next
fill →Network ID→ next→ next
Select allow both non secure and non secure dynamic updates
Right click on created reverse zone→ new pointer
enter host IP number e.g (184.108.40.206)
enter FQDN (www.chd.com)
220.127.116.11 Some DNS Commands
(i) c:>tracert www.yahoo.com command is used to check the path , a data packet follow from one router to another router. (ii) c:>nslookup command display the domain name with IP (works only when reverse lookup zone is set up). (iv)
c:>ipconfig /all This command display FQDN, IP address, MAC address.
(iv) c:>ipconfig /flushdns
This command flush or clear all the information in the cache that is retrieved from DNS server. (v) c:>ipconfig /displaydns Display the current contents or entries in the cache. (vi)
c:>ip config /register register any DNS name
3.6 DHCP SERVER DHCP (Dynamic Host Configuration Protocol) is a protocol that allocates IP address to computer on a network. DHCP centralized the management of IP address allocation and reduces human error associated with manual IP configuration. DHCP server supplies all the necessary networking param-eters. Two things are always handed out as a part of DHCP configuration: IP address and subnet mask. Further DHCP will frequently configure clients with optional values, such as a default gateway, DNS server address, and the address of a Window Internet Naming Server, if one is present. Scenario showing DHCP server IP address allocation.
3.6.1 Working of DHCP Server (i)
DHCP Super Scope
Exclusion IP Range
DHCP Lease Time
DHCP Scope Scope having the range of IP address for providing dynamic IP address to other computer. A group of IP address within a scope is called as DHCP scope. DHCP Super Scope A super scope is used to combine two or more scopes each serving different subnets, and can make the administration of several scopes on window 2003 DHCP server more manageable. Using super scope you can group multiple scopes as a single administrative
entity that allows the client to lease from either one. With this feature, a DHCP server can: •
Support DHCP clients on a single physical network segment where multiple logical IP networks are used. When more than one logical IP network is used on each physical subnet or network, such configuration is called multinets.
Support DHCP clients located on the far side of DHCP and BOOTP relay agent.
In multinet configuration, DHCP superscope can be used to group and activate individual scope ranges of IP addresses used on your network. In this way , a DHCP server computer can activate and provide leases from more than one scope to clients on a single physical network.
Exclusion IP range If you want to reserve some IP for any computer i.e if we want that from the series of 192.168.0.2 to 192.168.0.100 if we want that a series of IP addresses must not be assigned automatically then at can be done using exclusive IP range. DHCP Leased Time DHCP lease time is validity of IP address. By default DHCP lease time is 8 days minimum,1 day maximum 999 days, 23 hours to53 day. With in 8 days:After 80% of day clients demand new IP some times server refuse the client request. After 87.5% of days it will retry, and if the server did not give the new IP address then the client will receive APIPA address (Automatic Private IP Address). When a DHCP client is unable to locate a DHCP server, the client picks out a random IP address from the private APIPA address range of 169.254.*.*, with a subnet mask of 255.255.0.0. The 169.254.*.* IP range is private because that network number is not in use on the internet, it is random because the client generates an arbitrary host number for that network. The significance of APIPA is that DHCP client computers that cannot find a DHCP server can still be assigned an IP address and communicate with other computers on the same subnet mask that also cannot find DHCP server. It allows communication
when DHCP server is down or just plain not there. Note that APIPA does not assign a default gateway, and therefore it cannot communicate with any computer that lives on the other side of a router. IP Reservation There are some DHCP clients that you want to be the DHCP clients, but you will also want to make sure that they get same IP address every time. This can be done by statically filling the IP address. We can reserve IP address with the help of MAC address for a particular computer.
Installation Steps of DHCP Server
start→ control panel
add and remove program→ add and remove window components
select networking services and click on detail button
check box of DHCP server
Steps To Configure DHCP Server
start→ program→ administrative tool
create new scope in action menu→ new scope → next
give scope name→ next
give IP address range→ next
add exclusion name→ next
check lease duration→ next→ finish After DHCP server is configured, it is required to be authorized and DHCP scope
should be active. For that select DHCP server and click on authorize in action menu. Then right click on scope name and click on active.
On Client Side
Go to LAN card properties → select TCP/IP protocol→ properties
Select obtain IP address automatically
Go to command prompt (cmd)
Backup of DHCP Server
We can take backup of all the configuration in DHCP server with the help of administrator. Backup means to export the DHCP database to another system, as it is helpful in case due to any reason our data is corrupted or deleted, we can take our database from the place where it is stored. Steps of taking backup : •
Stop the DHCP server and disable the DHCP server services
Copy the DHCP server directory to a temporary location, say pen drive or on a new DHCP server.
3.6.3 DHCP Relay Agent The DHCP relay agent is a software that listen DHCP discover packet and forward to DHCP server. In window 2003 server system the DHCP relay agent can be enabled as a part of Routing and Remote Access (RRAS).
18.104.22.168 Steps To Configure DHCP Relay Agent •
Set the network, fill the IP address and select two LAN cards
Open Routing and Remote Access → enable Routing and Remote Access
Right click on general new routing protocols
Select DHCP relay agent
Select LAN card which is to be connected to the cross cable i.e L1
Right click on relay agent → properties
Enter IP address of DHCP server
add→ apply→ ok
With the release of Windows 2000, Microsoft introduced Active Directory, a scalable, robust directory service. Active Directory is used to create server based networking. Active Directory’s job is to store and make available a Directory database i.e information about the user, its class, name, address, mails, phone numbers, location. Active Directory is a technology created by Microsoft that provides a variety of network services like Directory Services, DNS based naming and other network information. Active Directory also allows administrator to assign policies, deploy software and apply critical updates to an organizations. Active Directory was previewed in 1999, released first with window 2000 server edition and revised to extend functionally and improve administration in Window 2003. Additional improvements were made in Window server 2003 and Window server 2008. The fundamental building block of Microsoft’s Directory services continues to be a domain. A domain is logically grouping of network resources, including shares, printers, groups and users accounts. The user account represents the individual to domain, and allows for different type of access and different types of tasks. Every users account is unique. It has uniqueness of the user account that allows administrator to control access for every member of domain. There are two types of users accounts: local account and domain account. Local accounts are maintained in the local database of a computer and cannot be used to grant access to network resources. Local users are primarily used to administer a computer or to allow several people to share a single computer that is not a member of a domain. Whereas domain users accounts are much more widely used in organizations that local user accounts because they allow for central administration and user can log onto any computer in the domain. Domain users accounts are stored in Active Directory.
3.7.1 Active Directory Services A computer network can be divided logically into two networking models. •
Difference Between Workgroup and Domain Table 9 Workgroup
1. It is a peer-to-peer networking 1. It is a server based networking model. model. 2.there is a centralized dedicated server 2. There is no client and no server. computer All computers are in equal status.
(DC)which controls all other computers called clients.
3.This model is recommended for small networks (upto 10 pcs).
3. This model is recommended for large networks.
4. There is no centralized Administration
is 4. There is centralized administration
and each PC can be administrated and managed from the server.
5.In this model, low grade operating system like 2000/xp professional, 5.In this model high grade operating win 98 etc can be used.
system ,like win2000/2003 server are used.
6. Workgroup can be given names like sales, HR, accounts etc.
6. Domain can also given names like abc.com, xyz.com etc.
7 Users accounts are created in each PC and are called as “Local Users”.
7.Users accounts are created on sever side DC and are called as ”Domain Users”.
Active Directory uses domain to hold objects, each domain has security boundary. Users must authenticates to the domain in which their users account resides before they can access resources, such as a shared folders. Active Directory also links related domains in a hierarchical structure and users can access resources in any of the domain in which their user account resides. The hierarchical structures of related domain is called a tree, and all domains in the tree share the same Domain Name System (DNS) namespace. All the domains and the trees in a single organization are called a forest. All domains in the forest share same schema.
Types of Domain
Domain Forest A forest is created when window 2k3 server computer is configured as a domain controller. A forest is a collection of multiple domain link together and relationship between the domains. Domain Tree A domain tree is made up when there is a parent child relationship between the domain in the forest. The child domain includes the complete parent domain name. a tree is a set of two or more domains sharing common namespace e.g we can create a parent domain and then child domain like mail.yahoo.com; where mail- child domain, yahoo- parent domain.
Fig 8: Structure of domain forest and domain tree Organization Unit (OU) Organization unit is the smallest unit in a domain network that can contain users, computer groups, shared folders, printers and group policy object in simple words. OU means department like sale department, accounts department like sales, accounts in a company OU can be used to apply different security policies to computer and users in different department. OU also helps in dividing administration among different administrator of managing only computer and users of sales department.
Types of Domain Controller (i)
PDC : Primary domain controller
ADC : Additional domain controller
BDC : Backup domain controller
Primary Domain Controller (PDC) This is the first domain controller, in this domain all entries are created in it like users account, group policy, Organization unit etc. All FSMO role are done in PDC.
Additional Domain Controller (ADC) It is a domain network, it is important to have more than one DC so that if one DC fails, the other DC will continue serving the client. There is also load balancing of Active Directory Service if we have more than one DC. The first DC we create is simply called PDC and if we create an extra DC then that DC is known as ADC. ADC has same configuration of AD as primary domain controller. All domain controllers in a domain networking are masters. We can make a change in the active directory of any domain controller and that change is replicated to all other domain controllers. Replication takes place among all the domain controllers and it is controlled automatically. If we create a user in the first domain controller, it is automatically created in the ADC because of replication. All the domain controllers in the domain networking are peers and this model is called as multi- master model .
Fig 9: Multi-Master Model
22.214.171.124 Requirements of Active Directory (i)
Window 2000/2003 server computer.
Atleast one NTFS partition.
Static IP address
Atleast 1GB free hard disk space
LAN card enabled and connected to the network
Install DNS, if not installed of Active Directory and configure it.
It should be noted that active directory cannot work without DNS.DNS is automatically installed and configured during the Active Directory installation.
126.96.36.199 Installation of Active Directory First of all fill the static IP address, then install DNS service into it and after that install the Active Directory •
start→ run→ dcpromo
Welcome to active directory → next→ next
Select domain controller for a new domain e.g (gmail.com)
Domain NETBIOS name (gmail.com)
Data folder, folder new tech directory service→ next (SYS VOL)
Click on install and configure the DNS server on this computer to use this DNS server as its preferred DNS server.
Tick on permission compatible only with window server
Enter the restore mode and the password
next→ next→ finish
now restart computer
Command used for the removal of Active Directory
start→ run→ dcpromo This command is also used to remove active directory, if after this command the active directory is not removed then type •
How to identify Active Directory installation •
Start → administrator tool After that if three options specified if come, it means that Active Directory
has been installed ─ Active Directory domain and trusts ─ Active Directory sites and services ─ Active Directory users and computer Open DNS console by •
Forward lookup zone ─ msdcs.exam.edu ─ start of authority (SOA) ─ name server (NS)
Now ping active directory with domain name like •
start→ run→ ping gmail.com
Backup of Active Director Active Directory backup come in use when there is some problem in active directory. If there is any problem in active directory then remove it and restore the backup. •
Select advance mode and untick that is already ticked
Selsct system state
Change backup path browse keep in your hardware and then send it to the pen drive
3.7.2 CHILD DOMAIN A domain is created say “xyz.com”. this domain is known as parent domain or the root domain. Now “chd.xyz.com” will be the child domain or the sub domain of xyz.com.
Fig 10 : parent-child relationship model A child domain is created to ease administration in a very large domain network. We can create the parent domain in the head office of the company and the child domain in the branch offices. Each branch office will have its own administrator to manage the users of the child domain present in the branch office. A true relationship is automatically created between the parent domain and the child domain. This means users in the child domain can access the file server of the
parent domain. Moreover users of either domain can use clients of either domain for logging in the domain but a user can always logon only in the domain in which his account resides, though he physically can use client pc of parent or client domain. Users of either domain can logon its own domain from either side but only when it use its own domain name. users of parent domain can communicate with child domain but he has to use its domain name for that.
Steps to create child domain
First of all install the active directory on pc1 i.e on the parent domain. Now make Tom user on it. On pc2 create the child domain, then make users on it, user- Ram Below are the steps to cerate child domain. •
Fill the IP address in the child domain
Now ping to the parent domain with the domain name (xyz.com)
Run →dcpromo→ ok
next→ select domain controller for a new domain
next→ select child domain and existing domain name (mcse.com)
enter username, password and domain name
enter user parent domain name also enter child domain name
enter complete DNS name i.e xyz.mcse.com
next→ next→ next→ next
it should be noted that parent domain can logon into child domain but on the other hand child domain cannot logon to the parent domain. Also parent domain can apply policies or security on the child domain. Make the client member by entering particular user with its domain name. •
First right click on My Computer
Write domain name →ok Now logoff start and then write user name - Tom Domain name - mcse.com
Again logoff and check the other user Start-user name- abc Domain name – mail.mcse.com
INTERNET SHAREING We can share a single internet connection to multiple computers with the help of
networking or internet sharing. There are four ways to share internet. (i)
ICS – Internet connection sharing
NAT – Network Address Translation
3.8.1 Direct Sharing Internet sharing can be done between computers directly, just by taking internet connection directly from ISP (Internet Server provider), then it is provided to ADSL model, ADSL modem is connected to the ISP through RJ-11 connector. Then it is
connected to the switch with RJ-45 connector. Switch, further connects computers those have to be provided with internet connection. The scenario for direct sharing is as shown in figure:
Fig: 11: Direct Sharing Scenario ADSL modem has IP address 192.168.1.1. All the PCs are assigned with a DNS (Domain Name Server) and GW (gateway) -192.168.1.1. Also DHCP (Dynamic Host Communication Protocol) is enabled which will provide IP addresses to the PCs automatically.
3.8.2 ICS (Internet Connection Sharing) Internet Connection sharing provides an alternate way to provide Internet Sharing. ICS requires a server with two network interfaces, one for the private internal network configured with IP 192.168.0.1 address and an adapter for public connection. ICS requires two connections in order to work: one public and one private i.e. ICS server
requires two LAN cards, Internal (Private) and External (Public). Internal LAN card uses Local LAN card (L2) and External LAN card (L1) is used by Internet. ICS is designed to be as simple as possible. ICS works on following windows: XP, Vista, 2K3 Server, 2k3 Server SP1.it doesn’t work on the server in which AD+SP1 is present. The scenario for ICS is shown below:
Fig 12: ICS scenario Note:- When we configure ICS then the local card detect 192.168.0.1 address automatically.
How to configure ICS •
Open network and sharing center
Click on Manage network connections
Right click on LAN Card which is used for internet- Properties
Click on sharing
3.8.3 Win Proxy Server Win Proxy is a third party software which is used for sharing internet and we can also block the web site with the help of win proxy. WIN Proxy supports all the three classes A, B, C also it is supported by all operating systems. The scenario for WIN proxy is shown below:
Fig 13: scenario of win proxy server In win proxy as shown in the scenario above we can share internet. First of all a ADSL modem is connected to the ISP (Internet Service Provider) by a RJ-11 connector and other end of ADSL modem is connected to the PC1 through RJ-45. Assign IP address 192.168.1.1 to the ADSL modem also enable the DHCP server and set the start IP address of 192.168.1.2 and end IP address of 192.168.1.254. Then after ADSL modem connect PC1, assign GW 192.168.1.1 and
3.8.4 NAT (Network Address Translation) If we have to connect many computers with a single IP address then we will use NAT. NAT exchange IP packet between local network and internet. The routing and remote access server of window 2K3 server provide us with a component known as NAT. By enabling NAT on a Server 2003 system, you allow connected users on a private system to
share a single connection to access a public network such as the internet i.e. NAT enable multiple client computer to connect the internet through a single publicly registered IP address. A NAT server translate private IP address to public addresses. NAT eliminates the need for large number of IP addresses by mapping externally assigned IP addresses.
Fig 14: NAT server When deploying NAT, it is needed to configure setting on both the client side and the server side. On the server side of NAT fill the IP address statically.
188.8.131.52 Steps to enable NAT server
Open internet → Tools→ Internet options
connections→ LAN settings
untick the IP and port address
ok→ ok→ give site name
On the client side of NAT, client side is configured to obtain IP addresses
automatically and then restart the client system. Assuming NAT is used for address assignment, the client system will receive TCP/IP information from the NAT server. The client information includes: •
IP address from 192.168.0.0 private addressing range
Subnet mask (255.255.255.0)
DNS server address, which would be the address of the NAT interface on the server.
With the client side configured, there are few things to do on NAT server: The first step to configure NAT server is to actually install the Routing and Remote Access Services. To do this, start the Routing and Remote Access Service Setup Wizard. •
Start→ administrator tools→ Routing & Remote Access
Right click on My Computer→ right click on computer name
Select option Configure and enable routing & remote access
Welcome to routing → next→ next
Select NAT→ next
Select LAN card which is to be connected to internet
From any of the four methods of internet sharing only method is used at a time to remove the other method •
go to start→ setting
add & remove
change/ remove, tick on remove.
3.9 VIRTUAL PRIVATE NETWORK (VPN) A virtual private network is used to convert public network address to private network. All the clients of VPN dial to public IP address of VPN server and receive private IP from virtual VPN dynamic host protocol (DHCP).in VPN one can have multiple virtual connections to a single IP address. This way ,one network card can host several inbound connections, rather than require a modem and telephone line for each simultaneous remote user.
Fig 15 : scenario of VPN server Using VPN server we can connect many private networks to internet services i.e the remote connection. We can create a private network through public network, we can use firewall for security and data encryption in VPN server.
3.9.1 VPN components (i)
VPN Server VPN server, serve as the end points of a VPN connection. When configuring a VPN server, you can allow access to just that server, or pass traffic through VPN server so that the remote user gain access the resources of the entire network. VPN Client VPN clients establish connection to VPN server. They can also be routers that obtain the router-to-router secure connection. VPN client software is included in all the modern window operating systems, including Window 2003 server. Router-to router VPN connection can be made from computers running server2003 and Windows 2000
running Routing and Remote Access. Additionally, any client that support PPTP or L2TP connections can be VPN clients of a window server 2003 system. WAN Options These provide the physical mechanism for passing data back and forth. These connections typically include such similar network technologies such as T1or frame relay. In order for VPN connections to be successful, the VPN client and VPN server must be connected to each other using either permanent WAN connection or by dialing into an internet server provider (ISP). Security Options Since a VPN uses a network that is generally open to the public, it is important that the data passed over the connection remain secure. To aid with secure communication routing and remote access supports such security measure as logon and domain security, data encryption, smart cards, IP packet filtering and caller ID.
3.9.2 Types of VPN (i)
PPTP (Point to Point Tunneling Protocol )
L2TP (Layer 2 Tunneling Protocol) according to CCNA.
Point to Point Tunneling Protocol (PPTP) PPTP is Microsoft’s legacy protocol for supporting VPN. It was developed in conjunction with other communications companies such as Robotics as an extension to the PPP protocol. PPTP encapsulates IP or IPX packets inside of PPP datagram’s. This means that you can remotely run programs that are dependent upon particular network protocols. One of the keys to remember about PPTP is that the protocol provides encryption capabilities, making it much safer to send information over nonsecure networks. Layer Two Tunneling Protocol (L2TP) L2TP is a standard based encapsulation protocol with roughly the same functionality as a Point-to-Point Tunneling Protocol (PPTP). One of the key differences
between Window’s server 2003 implementation of L2TPand it cousin PPTP is that L2TPis designed to run natively over IP networks only. This implementation of L2TP does not support native tunneling over X.25, frame relay, or ATM networks. Like PPTP, L2TPencapsulates Point-to-Point Protocol (PPP) frames, which then encapsulate IP or IPX protocols, allowing users to remotely run programs that are dependent on specific network protocols . But unlike the PPTP protocol, L2TP does not provide encryption of the data. For data security L2TPrelies on the services of another standards- based protocol, IPSec.
How to configure VPN
Routing and Remote access
Right click on computer name configure and enable Routing and Remote access
next→ select remote access (dial up or VPN)
next→ VPN→ next
select LAN card which is connected to internet (184.108.40.206) public IP
disable enable security → next
from a specific range of address→ next→new
enter the required range
ok→next→ no radius
Create users in VPN server
open user properties→ dial in → allow access
Working on Client Side
Right click on My Network Places→ properties
Double click on New Network Wizard→ next
Connect to network at my work place→ next
Virtual private network connection→ next
Enter company name (abc)→ next
Enter public IP address of VPN server→ next
Any one use →next
ROUTING It is a process of transferring information through an inter network i.e from one
network to another. Routing connect different networks having ID help in process of routing. The dial-in properties also allow for specific IP address to be assigned to a user. This is the only way in Window Server 2003 that you can assign a specific IP to a user. To assign a specific IP to a user, check the box next to assign A Static IP Address and enter a valid IP in the space provided. Static routing can also be specified as per user. By defining static routes, users can be limited to only specific parts of networks. In an internetwork a router must then about all the networks present in the for effort websites, there are hardware routers like CISCO. Even win 2003 server computer configured as router. In simple words Router is a computer with two network cards. These two network cards, then, are attached to two different logical IP networks. The routing table helps direct traffic that is passed through the router. Now when there is a router, also there is a routing table, there is a need to configure the router in order for that router to pass along traffic to the proper network. There are two ways the routing table can be built and modified: either manually or automatically.
3.10.1 Types of Routing (i)
220.127.116.11 Static Routing In this routing information required for routing is manually entered into the router by administrator.
How to configure LAN routing •
Enter the static IP in the router
Routing and Remote access
Right click on computer name (pcc1)
Configure and enable routing and remote access
next→ custom configuration
select LAN routing→next→ finish
yes and logon to see IP table route
Enable LAN routing Interface WAN IP 18.104.22.168 SNM 255.255.0.0 GW 22.214.171.124
enable LAN routing Interface WAN 10.0.0.0 IP 10.0.0.0 SNM 255.0.0.0 GW 126.96.36.199 Fig 16 : scenario for LAN routing
How to configure static routing
At Router R1: •
enable LAN routing
right click on static route
At Router R2: •
Enable LAN routing
Right click on static route
Fig 17 : static routing
188.8.131.52 Dynamic Routing
The other way to manage a router routing tables is to let the computer do it for you. Just like DHCP allocate IP addresses, configuring the dynamic routing protocol usually means less errors due to human error, and less administrative overhead. In dynamic routing, routing information is automatically entered in the router using protocols like RIP AND OSPF. These routing protocols used by Window Server 2003 use one of two kinds of algorithms to determine the best possible path for a packet to get to its destination, either distance vector or link state. RIP is used for small networks where as OSPF is used for large networks.
Routing Information Protocol (RIP) The distance vector protocol in use on Window 2003 is called Routing Information Protocol (RIP) for IP. This protocol was designed for the exchange of the routing information within a small to medium size IP network. When Router is enabled on Window 2003 machine, the routing table includes entries only for the networks that are physically connected. When RIP is enabled for an interface, the router will periodically send an announcement of its routing table to inform other RIP routers of the networks it can reach. RIP version1 uses broadcast packets for its announcement. RIP version2 offers an improvement and can be configured to use either multicast or broadcast packets when communicating with other routers. Also, RIP version2 offers more flexibility in subnetted and classless inter domain routing (CIDR) environments. The biggest advantage of RIPis its simplicity. With a few clicks in the Routing and Remote Access Server and MMC console, you can deploy RIP. With the RIP dynamic routing protocol installed on Window’s Server 2003, you get the following features: (i)
RIP version1 and version2, with the ability to configure individual network cards with separate versions.
Calculations used to avoid routing loops and speed recovery of the network whenever topology changes occur.
Route filters; you can configure RIP to except information from only certain networks, and also choose which routes will be shared with RIP routers.
Peer filters, which allow control over which router announcements are accepted.
Simple password authentication support.
But there are significant drawbacks, which makes RIP a poor, if not unusable solution for large networks. For example, the maximum hop count used for RIP routers is15, making network 16 hops away (or more) unreachable where RIP is concerned. Open Shortest Path First (OSPF) Where RIP is built to work to work in smaller networks, the Open Shortest Path First (OSPF) routing protocol is designed for large or very large networks. The goal is the same: information about connection to other networks is shared from one router to another. It offers several advantages over RIP, especially significant in large networks: (i)
Routes calculated with OSPF are always loop free.
OSPF can scale much more easily than RIP.
Reconfiguration for network topology changes is faster.
The biggest reason OSPF is the choice in large networks is its efficiency; instead of changing routing table via broadcast the way RIP does, OSPF configured routers maintain a map of the network. The mapping is called the link state database, OSPF routers keep the link state database up to date. Once changes have been made to link state database, an OSPF router’s link state database is recalculated. As the networks start to multiply, the size of the link state database increases, and a corresponding hit on router performance results. To combat this, OSPF sub divide the network into smaller sections, called areas. Areas are connected to each other through a backbone area, with each router only responsible for the link state database for those areas connected to the routers. Area Border Routers (ABRs) then connect one backbone area to another.
The biggest drawback of OSPF is its complexity; OSPF requires proper planning and is more difficult to configure and administer.
3.11 EXCHANGE SERVER Exchange server is a mail server, we can send and receive mail from one user to another user. Exchange server is the mail server of Microsoft.
3.11.1 Elements of Exchange Server Mail Server A server which helps to the users to send and receive mail is called mail server. Mail Box A storage place where senders and receivers mails are stored.
Exchange Version Table 10: Exchange Server with different operating systems Exchange Version
Exchange Server 5.5
WIN NT or 2000 server (without SP).
Exchange Server 2000
WIN NT or 2000 server (SP3,SP4) without (SP).
Exchange Server 2003
WIN 2000 Server or WIN2003 server (SP4) without SP.
Exchange server 2007
WIN2003 server or R2/WIN 2008 server with SP1.
Where SP stands for Service Pack. Service Pack are the services which are loaded externally to remove some bugs that come during installation of server CD.
3.11.3 Requirements for Exchange Server Protocols Required •
POP3 (Post Office Protocol) This protocol is used for receiving e- mails.
IMAE4 (Internet Messaging Access Protocol) This protocol is advance version of POP, this is also used to receive mail.
LMTP (Local Mail Transfer Protocol)/SMTP (Simple Mail Transfer Protocol) This protocol is used to send mails.
NNTP (Network News Transfer protocol) This protocol is used for transferring messages on internet.
Hardware Requirements •
Processor: min. 133MHz Rec. 733MHz
Other Requirements •
OS: 2k or 2k3 Server
Static IP address
DNS installation with AD zone
IIS installed with ASP.net, SMTP, NNTP and www service
3.12 Open System Interconnection (OSI) Model OSI model is the layer approach to design, develop and implement network. OSI provides following advantages: (i)
Development of new technology will be faster.
Devices from multiple vendors can communicate with each other.
Implementation and troubleshooting of network will be easy.
3.12.1 Description of Different Layers Application Layer Application layer accepts data and forward into the protocol stack. It creates user interface between application software and protocol stack. Presentation Layer This layer decides presentation format of the data. It also able to performs other function like compression/decompression and encryption/decryption. Session Layer This layer initiate, maintain and terminate sessions between different applications. Due to this layer multiple application software can be executed at the same time. Transport Layer Transport layer is responsible for connection oriented and connection less communication. Transport layer also performs other functions like (i)
Flow Control Buffering Windowing Multiplexing
(vi) Network Layer This layer performs function like logical addressing and path determination. Each networking device has a physical address that is MAC address. But logical addressing is easier to communicate on large size network. Logical addressing defines network address and host address. This type of addressing is used to simplify implementation of large network. Some
examples of logical addressing are: - IP addresses, IPX addresses etc. Network layer has different routing protocols like RIP, EIGRP, BGP, and ARP etc. to perform the path determination for different routing protocol. Network layer also perform other responsibilities like defining quality of service, fragmentation and protocol identification. Data Link Layer The functions of Data Link layer are divided into two sub layers •
Logical Link Control
Media Access Control
Logical Link Control defines the encapsulation that will be used by the NIC to delivered data to destination. Some examples of Logical Link Control are ARPA (Ethernet), 802.11 wi-fi.
Media Access Control defines methods to access the shared media and establish the identity with the help of MAC address. Some examples of Media Access Control are CSMA/CD, Token Passing.
Physical Layer Physical Layer is responsible to communicate bits over the media this layer deals with the standard defined for media and signals. This layer may also perform modulation and demodulation as required.
13.13.1 Router Architecture and its Key Component
Processor I/O Controller Memory Controller
Flash RAM O/S
NVRAM Startup Configuration
Fig 18 : Architecture of router Processor Speed: - 20 MHz to 1GHz Architecture: - RISC Reduce Instruction set computer Manufacturers: - Motorola, IBM, Power PC, Texas, Orion, Intel. Flash RAM Flash memory is just like a hard copy of the computer. Flash RAM is the permanent read/write memory. This memory is used to store one or more copies of router O/S. Router O/S is also called IOS (Internetwork Operating System).The size of Flash RAM in the router is 4MB to 256MB. This memory is Electrically Erasable Programmable Read Only Memory (EEPROM). NVRAM NVRAM is a “Non Volatile Random Access Memory”. It is used to store the startup configuration of the Router. It is on chip RAM, its size is 32kb.
RAM (Random Access Memory) It is a volatile memory. All the activities we do are stored in RAM,this means that it holds the running configuration. RAM of the router is divided into two logical parts. •
Primary RAM Primary RAM is used for: (i)
Running copy of IOS.
Address Resolution Protocol (ARP) table (IP address to MAC address)
Processor & other data structure
Shared RAM Shared RAM is used as a buffer memory to shared the data received from different interfaces. Size of RAM in a router may vary from 2 MB to 512 MB. The types of memory that may be present in a RAM are: (i)
DRAM -> Dynamic RAM
EDORAM -> Extended Data Out RAM
SDRAM -> Synchronous Dynamic RAM
ROM (Random Access Memory) It has four components: •
POST (Power on Self Test) It performs hardware testing.
BOOT Strap Boot strap specifies from where and which inter operating system is to be
Mini IOS Cisco 2500, 1600
Router Interfaces & Ports
Interface is used to connect LAN networks or wan networks to the router. Interface will use protocol stacks to send/receive data. Ports are used for the configuration of routers. Ports are not used to connect different networks. The primary purpose of port is the management of router. 33333333
Table 11: Router interfaces and connectors
AUI – Attachment Unit Interface EPABX – Electronic Private Automatic Branch PSTN – Public Services Telephone Network 184.108.40.206 Router Ports Table 12: Router Ports
Modes of Router
When we access router command prompt the router will display different modes. According to the modes, privileges and rights are assigned to the user.
User mode Router> In this mode, we can display basic parameter and status of the router we can test connectivity and perform telnet to other devices. In this mode we are not able to change and save router configuration.
Privileged mode Router# In this mode, we can display all information, configuration, perform administration task, debugging, testing and connectivity with other devices. We are not able to perform here configuration editing of the router. The command to enter in this mode is ‘enable’. We have to enter enable password or enable secret password to enter in this mode. Enable secret has more priority
than enable password. If both passwords are configured then only enable secret will work.
Global configuration Route(config)# This mode is used for the configuration of global parameters in the router. Global parameters applied to the entire router. All the changes are performed in this mode. But here we cannot see and save the changes. For e.g: - router hostname or access list of router, password, Banner, Routing, Security. The command to enter in this mode is ‘configure terminal’
Line configuration mode In this mode we can set the password of the user mode, i.e to set user mode password .This mode is used to configure lines like console, vty and auxiliary. There are main types of line that are configured. (i)
Console Router(config)#line console 0
(ii) Auxiliary Router(config)#line aux 0 (iii) Telnet or vty Router(config)#line vty 0 4
Interface configuration mode In this mode we can set ip addresses of the interfaces. This mode is used to configure router interfaces. For e.g:- Ethernet, Serial, BRI etc. Router(config)#interface Router(config)#interface serial 1
Routing configuration mode This mode is used to configure routing protocol like RIP, EIGRP, OSPF etc. Router(config)#router 
Router(config)#router rip Router(config)#router eigrp 10
There are five types of password available in a router
Console Password router#configure terminal router(config)#line console 0 router(config-line)#password router(config-line)#login router(config-line)#exit To erase password do all steps with no command.
Vty Password router>enable router#configure terminal router(config)#line vty 0 4 router(config-line)#password router(config-line)#login router(config-line)#exit
Auxiliary Password router#configure terminal router(config)#line Aux 0 router(config-line)#password router(config-line)#login router(config-line)#exit
Enable Password router>enable router#configure terminal
router(config)#enable password router(config)#exit
Enable Secret Password Enable Password is the clear text password. It is stored as clear text in configuration where as enable secret password is the encrypted password. Router>enable Router#configure terminal Router(config)#enable secret Router(config)#exit
Encryption all passwords All passwords other than enable secret password are clear text password. The command to encrypt all password are Router#configure terminal Router(config)#service password-encryption
3.13.5 Managing Configuration There are two types of configuration present in a router (i)
Startup configuration is stored in the NVRAM. Startup configuration is used to save settings in a router. Startup configuration is loaded at the time of booting in to the Primary RAM. Running Configuration is present in the Primary RAM wherever we run a command for configuration, this command is written in the running configuration.
To save configuration Router#copy running-configuration startup-configuration Or Router#write
To abort configuration Router#copy startup-configuration running-configuration
To display running-configuration Router#show running-configuration
To display startup configuration Router#show startup-configuration
Configuring Host Name Router#configure terminal Router(config)#hostname #exit or end or /\z Router#config terminal Router(config)#hostname r1 R1(config)#
Configuration Interfaces Interfaces configuration is one of the most important part of the router configuration. By default, all interfaces of Cisco router are in disabled mode. We have to use different commands as our requirement to enable and configure the interface. Router#configure terminal Router(config)#interface Router(config-if)#ip address Router(config-if)#no shutdown Router(config-if)#exit
To display interface status Router#show interfaces (to show all interfaces) Router#show interface This command will display following parameters about an interface (1)
Hardware type / manufacturer
Load ( Tx load Rx load)
ARP type (if applicable)
Configuring optional parameter on WAN interface Router#configure terminal Router(config)#interfac Router(config-if)#encapsulation Router(config-if)#clock rate Router(config-if)#end
Command displaying history of Router • To display commands present in history Router#show history
• To display history size Router#show terminal
• To change history size Router#config terminal Router(config)#line console 0 Router(config-if)#history size Router(config-if)#exit
Configuring Banners Banners are just a message that can appear at different prompts according to the type. Different banners are: •
Message of the day (motd) This banner appear at every access method
Login Appear before login prompt
Exec Appear after we enter to the execution mode
Incoming Appear for incoming connections
Syntax:Router#config terminal Router(config)#banner
Example Router#config terminal Router(config)#banner motd $ This router is distribution 3600 router connected to Reliance $ Router(config)#
To set time in router We can configure router clock with the help of two methods: (i)
Configure clock locally
Configure clock on NTP server (Network Time Protocol)
Router does not have battery to save the clock setting. So that clock will reset to the default on reboot.
To display clock Router#show clock
To configure clock Router#clock set hh:mm:ss day month year Router#clock set 7:15:10 9 June 2009
To configure clock from NTP server Router#config terminal Router(config)#ntp server Router(config)#exit C:\>ping pool.ntp.org To get ntp server ip from internet C:\>route print
SUBNETTING Subnetting is a process or a technique to divide large and complex networks into
smaller parts or smaller networks and each network is called as subnet. Subnetting is done to reduce the wastage of IP addresses ie instead of having a single huge network for an organization smaller networks are created within a given huge network. Subnetting allows the user to create multiple logical networks within a single Class A, B or C based networks. In subnetting, the IPv4 address is broken into two parts; network id and host id. This process borrows bits from the host id field. In this process, the network size does not shrink but the size of hosts per network shrinks in order to include sub-networks within the network. 333333
Advantages of subnetting
Size of the physical networks is reduced and hence easy to manage.
Reduce network traffic.
Easy to troubleshoot.
Reduce the wastage of IP address.
Subnet Mask A subnet mask specifies the part of IP address that is to be used for identifying a sub network. A subnet mask when logically ANDed with IPaddress provides a 32- bit network address. This binary address gives the first address in the subnet block specified in the large network.
Default Mask Classfull addresses consists of three classes; Class A, Class B, Class C used for subnet.Each class has a default subnet mask C lass A consists of eight 1s in the network address field and 24 0s in remaining field, Class B consists of 16 1s in network address field and 16 0s in remaining field, and Class C cointains 24 1s in the network address field and remaining 8 bytes as 0s. the default address mask in binary and dotted-decimal is shown in the table
To Calculate the Subnet Mask 1. Identify the class of address assigned. For this example the class of IP address is Class B.
2. check the default address mask for the appropriate class and convert it to binary format .for this example the default address mask is 255.255.0.0 and the equivalent binary format is; 11111111.11111111.00000000.00000000 3. check the no. of 1s in the default mask. E.g this address contains 16 1s in class B, 16 bits 2 octat are for net id and the last 16 bits 2 octates are for host id. 4. now if we need 9 subnets. This no. 9 is not a power of 2. the next no. that is power of 2 and greater than 2 is 16. So, we require 4 extra 4 extra 1s in the network field which has to be borrowed from the host id field. 5. the total no. of 1s is 16+4=20, as 16 1s are from network id and 4 1s are of additional bits required for subnetwork. The no. of 0s in the n/w is 32-20=12. which defines whole address. 6. hence address is given as 11111111.11111111.11110000.00000000 and in decimal format can be given as 255.255.240.0 Table 14: decimal and binary values of subnet mask
00000000 0 128 192 224 240 248 252 254 255
10000000 11000000 11100000 11110000 11111000 11111100 11111110 11111111
Types of Subnetting
Fixed Length Subnet Mask (FLSM)
Variable Length Subnet Mask (VLSM)
Steps of Subnetting for FLSM For IP address 192.168.10.0 (Class C) Step 1: •
Identify the total no. of subnets 2^n = no.of subnets
Where n are the no.s and borrowed bytes from host ID portion. Let we are given that we have to make 4 subnets. Therefore 2^n =4 i.e n=2
Step 2: •
To idettify the total no. of the valid hosts for each subnet.
2^m-2= no.of valid hosts. Where m are the remaining no. of bits in host ID 2^62=62
Step 3: •
Calculate the subnet mask and range
11111111.11111111.11111111.1100000000 ie 255.255.255.192 •
step 4: •
Identify the total no of subnets, no. of valid hosts and the broadcast address.
Table 15: showing subnet mask, valid hosts, broadcast address Subnetwork
Broadcast Address to
192.168.10.127 to 192.168.10.191 to 192.168.10.255
VLSM In VLSM to allocate IP addresses to subnets depending upon the no. of hosts. The network having more no of hosts is given priority and the one having least no of host comes at last and for each network the subnet is assigned separately. As in the scenario given:
Fig 19: variable subnet mask 3.15 TELNET Telnet stands for terminal network, telephone network, terminal encapsulation on the network. Purpose of Telnet is to access the remote device in order to configure it. It provides textual access of the remote device. It uses the services of TCP. Telnet service is used where small bandwidth is low. It provides textual access of the remote device. Port number of Telnet is 23.
3.15.1 To Access the Device Remotely For this purpose we have to assign the IP addresses to the PCs and the interfaces. For Telnet the Routers are to be configured with RIP version1 , so that the device can ping each other. Also DCE cable is used to connect the Routers. The serial link should have the speed of 64K also apply vty password and enable secret password. Set up the Routers so that they can manage via Telnet. First of all select the PCs and the routers connect the ports to the router, double click on router, switch off the router if it is on. Then select the serial port according to the routers, switch on the router. Select the cable to connect the Routers. Router to Router connections are made by the serial cable, so go on first Router select the serial port as s0/1/0 in the scenario, then go to the other Router and connect the serial cable at interface s1/0. Accordingly connect the third Router with interfaces s1/1 and s1/2.
Now connect the PCs to the routers, to do this first select the console cable, click on the PC select RS232 option, then connect it on the Router and select console cable. Now select cross- over cable on the PC select Fast Ethernet option and on the Router select f0/0 option now as the PCs and Routers are connected to each other assign IP addresses to the PCs and the Routers. According to the fig set the IP addresses of the PCs→ double click on the PC→ choose the option of desktop→ IP configuration. Now set the IP address, subnet mask, and the default gateway. Like wise set the IP address of all the PCs. Now set the IP address of the interfaces of router.
3.15.2 Commands to assign IP addresses to the interfaces: At Router1: Router> Router>enable Router#configure terminal Router(config)#interface f0/0 Router(config-if)#ip address 10.0.0.1 255.0.0.0 Router(config-if)#no shutdown
Fig 20: scenario of Telnet
Router# Router#configure terminal Router(config)#interface s0/1/0 Router(config-if)#ip address 220.127.116.11 255.0.0.0 Router(config-if)#no shutdown Router(config)#interface s0/1/0 Router(config-if)#clock rate 64000 Router(config-if)#no shutdown Now to check the assigned IPaddresses to the interfaces the command used is Router#show ip interface brief
At router 2: Router#configure terminal Router(config)#interface f0/0 Router(config-if)#ip address 18.104.22.168 255.0.0.0 Router(config-if)#no shutdown Router# Router#configure terminal Router(config)#interface s1/0 Router(config-if)#ip address 22.214.171.124 255.0.0.0 Router(config-if)#no shutdown Router#configure terminal Router(config)#interface s1/1 Router(config-if)#ip address 126.96.36.199 255.0.0.0 Router(config-if)#no shutdown Router(config)#interface s1/1 Router(config-if)#clock rate 64000 Router(config-if)#no shutdown
At router 3: Router#configure terminal Router(config)#interface f0/0 Router(config-if)#ip address 188.8.131.52 255.0.0.0 Router(config-if)#no shutdown Router# Router#configure terminal Router(config)#interface s1/0 Router(config-if)#ip address 184.108.40.206 255.0.0.0 Router(config-if)#no shutdown
To Telnet a device from Router At all the Routers use these commands Router(config)#line vty 0 4 Router(config-line)#password cobra Router(config-line)#login Router(config)#enable password cobra Router(config)#enable secret cobra1
To telnet a device from router Router#telnet Or Router>telnet
To exit from telnet session Router#exit
To exit from a hanged telnet session Ctrl+shft+6 Or
To display connected session Router#show sessions This command shows those sessions, which are created or connected by us. If we want anyone can telnet our router without password then on the line vty type command “No Login”.
3.16 ROUTING Routing is a process or technique to identify the path from one network to another. Routers don’t really care about hosts—they only care about networks and the best path to each network. To route the packet the router must know the following things: •
Neighbour device from witch it can learn about remote Networking.
Possible number of routers to reach the destination.
Best route to reach the destination.
How to maintain & verify the routing information.
3.16.1 TYPES OF ROUTING •
220.127.116.11 STATIC ROUTING In static routing an administrator specifies all the routes to reach the destination. Static routing occurs when you manually add routes in each router’s routing table.By default, Static routes have an Administrative Distance (AD) of 1
Features There is no overhead on the router CPU. There is no bandwidth usage between routers. It adds security, because the administrator can choose to allow routing access to certain networks only.
Advantages of static routing (1) Fast and efficient. (2) More control over selected path. (3) Less overhead for router. (4) Bandwidth of interfaces is not consumed in routing updates.
Disadvantages of static routing (1) More overheads on administrator. (2) Load balancing is not easily possible. (3) In case of topology change routing table has to be change manually.
Syntax for Static Routing Router (config)# ip route [Permanent].
To check the routing table of router Router # show ip route
Fig 21: scenario of static routing
Static routing of router (R1) Router(config)#ip route 18.104.22.168 255.0.0.0 22.214.171.124 Router(config)#ip route 126.96.36.199 255.0.0.0 188.8.131.52 Router(config)#ip route 184.108.40.206 255.0.0.0 220.127.116.11 Router(config)#interface so/1/0 Router(config)# clock rate 64000 Router # show ip route
Static routing of router (R2) Router(config)#ip route 10.0.0.0 255.0.0.0 18.104.22.168 Router(config)#ip route 22.214.171.124 255.0.0.0 126.96.36.199 Router#show ip route Router(config)#interface s1/0 Router(config)# clock rate 64000 Router(config)#interface s1/1
Router(config)#clock rate 64000 Router#show ip route
Static routing of router (R3) Router(config)#ip route 10.0.0.0 255.0.0.0 188.8.131.52 Router(config)#ip route 184.108.40.206 255.0.0.0 220.127.116.11 Router(config)#ip route 18.104.22.168 255.0.0.0 22.214.171.124 Router(config)#interface s1/0 Router(config)# clock rate 64000 Router#show ip route
DEFAULT ROUTING Default routing is used to send packets with a remote destination network
not in the routing table to the next-hop route. Default routing is also a type of static routing which reduces the routing overhead & default routing is also used with stub networks. Stub networks are those having a single exit interface. Default routing is also used for unknown destination. A special address is used to perform the default routing ie 0.0.0.0 The scenario for default routing is same and but the commands used at the routers having single exit interface like R1 and R3 have different commands.
At Router (R1) Router(config)#ip route 0.0.0.0 0.0.0.0 126.96.36.199 Router#show ip route
At Router (R3) Router(config)#ip route 0.0.0.0 0.0.0.0 188.8.131.52 Router#show ip route
DYNAMIC ROUTING Dynamic routing is when protocols are used to find networks and update
routing table on routers. A routing protocol defines the set of rules used by router when it communicates routing information between neighbor routers. In dynamic routing, we will enable a routing protocol on router. This protocol will send its routing information to the neighbor router. The neighbors will analyze the information and write new routes to the routing table. The routers will pass routing information receive from one router to other router also. If there are more than one path available then routes are compared and best path is selected. Some examples of dynamic protocol are: RIP, IGRP, EIGRP, OSPF There are two type of routing protocols used in internetwors:
• Interior Gateway Protocols (IGPs) IGPs are used to exchange routing information with routers in the same Autonomous System(AS) number. Routing which is performed within a single autonomous system is known as interior routing. The protocol that are used to perform this type of routing are known as IGP(Interior Gateway Protocol). These protocols are:(i)
RIPv1 (Routing Information Protocol Version 1)
RIPv2 (Routing Information Protocol Version 2)
EIGRP (Enhanced Interior Gateway Routing Protocol)
OSPF (Open Shortest Path First)
IS-IS (Intermediate System to Intermediate System)
• Exterior Gateway Protocols (EGPs) EGPs are used to communicate between different Autonomous System. Protocol that used to do this type of routing are called exterior gateway protocols.
Autonomous System:- An autonomous system is a collection of networks under a common administrative domain, which basically means that all routers sharing the same routing table information are in the same AS.
3.16.2 Routing Protocol Basics
Administrative Distances The Administrative Distance (AD) is used to rate the trustworthiness of routing
information received on a router from a neighbor router. An Administrative Distance is an integer from 0 to 255, where 0 is the most trusted and 255 means no traffic will be passed via this route. If a router receives two updates listing he sane remote network, the first thing the router checks is the AD. If one of the advertised routes has lower AD than the other, then the route with the lowest AD will be placed in the routing table.If both advertised routes to the same network have the same AD, then routing protocol metrics (such as hop count or bandwidth of the lines) will be used to find the best path to the remote network. The advertised route with the lowest metric will be placed in the routing table. But if both advertised routes have the same AD as well as the same metrics, then the routing protocol will load-balance in the remote network.
This route will never be used
Classes of Routing Protocols
There are three classes of Routing Protocol (i)
Distance vector protocol
Link state protocol
• Distance vector protocol The Distance-vector protocols find the best path to remote network by judging distance. Each time a packet goes through a router, that’s called a hop. The route with the least number of hops to the network is determined to be the best route. The vector indicates the direction to the remote network. They send the entire routing table to directly connected neighbors. Ex: RIP, IGRP. The distance-vector routing algorithm passes complete routing table contents to neighboring routers. A router receiving an update from a neighbor router believes the information about remote networks without actually finding out for itself. It’s possible to have network that has multiple links to the same remote network, and if that’s the case, the administrative distance is checked first. If the AD is the
same, the protocol will have to use other metrics to determine the best path to use to that remote network.
Fig 16: Routing table
Fig 23 : Routing table of covered networks •
Distance-vector routing protocols keep track of any changes to the internet work by broadcasting periodic routing updates out all active interfaces. This broadcast includes the complete routing table. Routing loops can occur because a every router isn’t updated simultaneously.
Routing Loops Example
Fig 24: Routing loops The interface to Network 5 fails. All routers know about Network 5 from Router E. Router A, in its tables, has a path to Network 5 through Router B. When Network 5 fails, Router E tells Router C. This causes Router C to stop routing to Network 5 through Router E. But Routers A, B, and D don’t know about Network 5 yet, so they keep sending out update information. Router C will eventually send out its update and cause B to stop routing to Network 5, but Routers A and D are still not updated. To them, it appears that Network 5 is still available through Router B with a metric of 3.The problem occurs when Router A sends out its regular 30-second “Hello, I’m still here—these are the links I know about” message, which includes the ability to reach Network 5 and now Routers B and D receive the wonderful news that Network 5 can be reached from Router A, so Routers B and D then send out the
information that Network 5 is available. Any packet destined for Network 5 will go to Router A, to Router B, and then back to Router A. This is a routing loop. •
Link state protocol Also called shortest-path-first protocols, the routers each create three
separate tables. One keeps track of directly attached neighbors, one determines the topology of the entire internet work, and one is used as the routing tables. Link state routers know more about the internet work than any distance-vector routing protocol. Link state protocols send updates containing the state of their own links to all other routers on the network Ex: OSPF •
Hybrid protocol Hybrid protocol use aspects of both distance-vector and link state protocol.
RIP (Routing Information Protocol) Routing Information Protocol is a true distance-vector routing protocol. It
is an IGB (Inter Gateway Protocol). It sends the complete routing table out to all active interfaces every 30 seconds to its immediate neighbour. This is slow convergence means that one router sends a request to other about its route or network get networks which are not assigned to it after all thee three routers have same networks, this process is repeated to send and receive request so it is called slow convergence RIP only uses hop count to determine the best way to remote network, but it has a maximum allowable hop count of 0-15 by default, meaning that 16 is deemed unreachable. RIP version 1 uses only class full routing, which means that all devices in the network must use the same subnet mask. RIP version 2 provides something called prefix routing, and does send subnet mask information with the route updates. This is called classless routing.
Hop Count It is a way of measurement. Hop count limit is15.This routing supports only 15
routers, if there is one more router in the network then this routing will fails. •
Default administrative distance (120)
Timers of RIP (i)
Flush out timers.
Route update timer Router update timer sets the interval 30 seconds between periodic routing updates, in which the router sends a complete copy of its routing table out to all neighbors.
Router invalid timers A router invalid timer determines the length of time that must elapse 180 seconds before a router determines that a route has become invalid. It will come to this conclusion if it hasn’t heard any updates about a particular route for that period. When that happens, thee router will send out updates to all its neighbors letting them know that the route is invalid.
Hold-down timer This sets the amount of time during which routing information is suppressed. Routers will enter into the hold-down state when an update packet is received that indicated the route is unreachable. This continues until entire an update packet is received with a better metric or until the hold-down timer expires. The default is 180 seconds.
Route flush timer Route flush timers’ sets the time between a route becoming invalid and its interval from the routing table 240 seconds. Before it’s removed from the table, the router notifies its neighbors of that route’s impending demise. The value of the route invalid timer must be less than that of the route flush timers.
Difference between RIPV1 & RIPV2
Steps to do routing (version 1) At router 1 Router(config)# router rip Router(config-router)#network 10.0.0.0 Router(config-router)#network 184.108.40.206
Router#show ip route
At router 2 Router(config)# router rip Router(config-router)#network 220.127.116.11 Router(config-router)# network 18.104.22.168 Router(config-router)# network 22.214.171.124 Router#show ip route
At router 3 Router(config)# router rip Router(config-router)#network 126.96.36.199 Router(config-router)# network 188.8.131.52 Router#show ip route
3.16.4 IGRP ( Interior Gateway Protocol) Interior Gateway Routing Protocol (IGRP) is a Cisco-proprietary distance-vector routing protocol. To use IGRP, all your routers must be Cisco routers. IGRP has a maximum hop count of 255 with a default of 100. IGRP uses bandwidth and delay of the line by default as a metric for determining the best route to an internetwork. Reliability, load, and maximum transmission unit (MTU) can also be used, although they are not used by default. Table 18 : Difference between IGRP and RIP IGRP
Can be used in large internetworks
Works best in smaller networks
Uses an autonomous system number for Does not yse aytibiniys system numbers activation Gives a full route table update every 90 Gives full route table update every 30 seconds
Has an administrative distance of 100
Has an administrative distance of 120
Uses bandwidth and delay of the line as Uses only hop count to determine the best metric (lowest composite metric),with a path to a remote network, with 15 hops maximum hop count of 255
being the maximum
IGRP Timers To control performance, IGRP includes the following timers with default settings: •
Update timers These specify how frequently routing-update messages should be sent. The
default is 90 seconds. •
Invalid timers These specify how long a router should wait before declaring a route invalid if it
doesn’t receive a specific update about it. The default is three times the update period. •
Hold down timers These specify the hold down period. The default is three times the update timer
period plus 10 seconds.
• Flush timers These indicate how much time should pass before a route should be flushed from the routing table. The default is seven times the routing update period. If the update timer is 90 seconds by default, then 7 × 90 = 630 seconds elapse before a route will be flushed from the route table.
At Router 1 R1(config)#router igrp 10 R1(config-router)#network 10.0.0.0 R1(config-router)#network 184.108.40.206 R1#show ip route
At Router 2 R2(config)#router igrp 10 R2(config-router)#network 220.127.116.11 R2(config-router)#network 18.104.22.168 R2(config-router)#network 22.214.171.124 R2#show ip route
At Router 3 R1(config)#router igrp 10 R1(config-router)#network 126.96.36.199 R1(config-router)#network 188.8.131.52 R1#show ip route
EIGRP(Enhanced Interior Routing Protocol) Enhanced IGRP (EIGRP) is a classless, enhanced distance-vector protocol
that gives us a real edge over IGRP. Like IGRP, EIGRP uses the concept of an autonomous system to describe the set of contiguous routers that run the same routing protocol and share routing information. But unlike IGRP, EIGRP includes the subnet mask in its route updates. The advertisement of subnet information allows us to use VLSM and summarization when designing our networks. EIGRP is sometimes referred to as a hybrid routing protocol because it has characteristics of both distance-vector and link-state protocols. It sends traditional distance-vector updates containing information about networks plus the cost of reaching them from the perspective of the adverting router. EIGRP has a maximum hop count of 255.
Powerful features that make EIGRP a real standout from IGRP
Support for IP, IPX, and AppleTalk via protocol-dependent modules Considered classless (same as RIPv2 and OSP
Support for VLSM/CIDR
Support for summaries and discontiguous networks
Efficient neighbor discovery
Communication via Reliable Transport Protocol (RTP)
Best path selection via Diffusing Update Algorithm (DUAL) Cisco calls EIGRP a distance vector routing protocol, or sometimes an
advanced distance vector or even a hybrid routing protocol. EIGRP supports different Network layer protocols through the use of protocol-dependent modules (PDMs). Each EIGRP PDM will maintain a separate series of tables containing the routing information that applies to a specific protocol. It means that there will be IP/EIGRP tables, IPX/EIGRP tables, and AppleTalk/EIGRP tables.
Neighbor Discovery Before EIGRP routers are willing to exchange routes with each other, they must become neighbors. There are three conditions that must be met for neighborship establishment: Hello or ACK received AS numbers match Identical metrics (K values) To maintain the neighborship relationship, EIGRP routers must also continue receiving Hellos from their neighbors. EIGRP routers that belong to different autonomous systems (ASes) don’t automatically share routing information and they don’t become neighbors. The only time EIGRP advertises its entire routing table is when it discovers a new neighbor and forms an adjacency with it through the exchange of Hello packets. When this happens, both neighbors advertise their entire routing tables to one another. After
each has learned its neighbor’s routes, only changes to the routing table are propagated from then on. EIGRP maintains three tables containing information about the internetworks. (i) Neighbor Table Records information about routers with whom neighborship relationships have been formed. (ii) Topology Table Stores the route advertisements about every route in the internetwork received from each neighbor.
EIGRP Metrics Another really sweet thing about EIGRP is that unlike many other protocols that use a single factor to compare routes and select the best possible path, EIGRP can use a combination of four:
OSPF (Open Shortest Path First) Open Shortest Path First (OSPF) is an open standards routing protocol that’s been
implemented by a wide variety of network vendors, including Cisco. This works by using the Dijkstra algorithm. First, a shortest path tree is constructed, and then the routing table is populated with the resulting best paths. OSPF converges quickly, although perhaps not as quickly as EIGRP, and it supports multiple, equal-cost routes to the same destination. But unlike EIGRP, it only supports IP routing. OSPF is an IGP protocol. It is a link state routing protocol. It is supported by many operating systems. Its default AD is 110, hop count limit is unlimited.
It is classless routing protocol, supports VLSM/CIDR. By default the highest IP address of interface will be elected as Router id.
OSPF provides the following features
Consists of areas and autonomous systems
Minimizes routing update traffic
Has unlimited hop count
Allows multi-vendor deployment (open standard) OSPF is supposed to be designed in a hierarchical fashion, which basically means
that you can separate the larger internetwork into smaller internetworks called areas. This is the best design for OSPF. The reasons for creating OSPF in a hierarchical design include: •
To decrease routing overhead
To speed up convergence
To confine network instability to single areas of the network Each router in the network connects to the backbone called area 0, or the
backbone area. OSPF must have an area 0, and all routers should connect to this area if at all possible. But routers that connect other areas to the backbone within an AS are called Area Border Routers (ABRs). Still, at least one interface must be in area 0. OSPF runs inside an autonomous system, but can also connect multiple autonomous systems together. The router that connects these ASes together is called an Autonomous System Boundary Router (ASBR).
OSPF Terminology •
A link is a network or router interface assigned to any given network. When an interface is added to the OSPF process, it’s considered by OSPF to be a link. •
Router ID The Router ID (RID) is an IP address used to identify the router. Cisco chooses
the Router ID by using the highest IP address of all configured loopback interfaces. If no loopback interfaces are configured with addresses, OSPF will choose the highest IP address of all active physical interfaces. •
Neighbors Neighbors are two or more routers that have an interface on a common
network,such as two routers connected on a point-to-point serial link. •
Adjacency An adjacency is a relationship between two OSPF routers that permits the direct
exchange of route updates. OSPF is really picky about sharing routing information— unlike EIGRP, which directly shares routes with all of its neighbors. Instead, OSPF directly shares routes only with neighbors that have also established adjacencies. And not all neighbors will become adjacent—this depends upon both the type of network and the configuration of the routers.
OSPF Topologies database The topology database contains information from all of the Link State Advertisement packets that have been received for an area. The router uses the information from the topology database as input into the Dijkstra algorithm that computes the shortest path to every network. LSA packets are used to update and maintain the topology database. A Link State Advertisement (LSA) is an OSPF data packet containing link-state and routing information that’s shared among OSPF routers. There are different types of LSA packets. An OSPF router will exchange LSA packets only with routers to which it has established adjacencies. A designated router (DR) is elected whenever OSPF routers are connected to the same multi-access network. A prime example is an Ethernet LAN.
A backup designated router (BDR) is a hot standby for the DR on multi-access links The BDR receives all routing updates from OSPF adjacent routers, but doesn’t flood LSA updates. OSPF areas An OSPF area is a grouping of contiguous networks and routers. All routers in the same area share a common Area ID. Broadcast (multi-access) Broadcast (multi-access) networks such as Ethernet allow multiple devices to connect to (or access) the same network, as well as provide a broadcast ability in which a single packet is delivered to all nodes on the network. In OSPF, a DR and a BDR must be elected for each broadcast multi-access network. Non-broadcast multi-access Non-Broadcast Multi-Access (NBMA) networks are types such as Frame Relay, X.25, and Asynchronous Transfer Mode (ATM). These networks allow for multi-access, but have no broadcast ability like Ethernet. So, NBMA networks require special OSPF configuration to function properly and neighbor relationships must be defined. •
Point-to-point Point-to-point refers to a type of network topology consisting of a direct
connection between two routers that provides a single communication path. The point-topoint connection can be physical, as in a serial cable directly connecting two routers, or it can be logical. •
Point-to-multipoint Point-to-multipoint refers to a type of network topology consisting of a series of
connections between a single interface on one router and multiple destination routers. All of the interfaces on all of the routers sharing the point-to-multipoint connection belong to the same network. As with point-to-point, no DRs or BDRs are needed.
SPF Tree Calculation Within an area, each router calculates the best/shortest path to every network in that same area. This calculation is based upon the information collected in the topology database and an algorithm called shortest path first (SPF) OSPF uses a metric referred to as cost. A cost is associated with every outgoing interface included in an SPF tree. The cost of the entire path is the sum of costs of the outgoing interfaces along the path. Cisco uses a simple equation of 108/ bandwidth.The bandwidth is the configured bandwidth for the interface. Using this rule, a 100Mbps Fast Ethernet interface would have a default OSPF cost of 1 and a 10Mbps Ethernet interface would have a cost of 10. An interface set with a bandwidth of 64,000 would have a default cost of 1563.
Benefits of OSPF (i)
Minimum routing updates.
Priorities on all the CISCO routers the priority is 1.
The routers having highest IP address become BRD(Border Destination Router)
Steps to apply OSPF Syntax: Router(config)#router ospf Router(config-router)#network area
Fig 25: OSPF Scenario
At Router r1 Router(config)#router ospf 1 Router(config-router)#network 10.0.0.0 0.255.255.255 area 0 Router(config-router)#network 10.0.0.0 0.255.255.255 area 0 Router(config)#interface s0/1/0 Router(config-if)#clock rate 64000 Router#show ip route
At Router r1 Router(config)#router ospf 2 Router(config-router)#network
Router(config-router)#network 184.108.40.206 0.255.255.255 area 0 Router(config-router)#network 220.127.116.11 0.255.255.255 area 0 Router(config)#interface s0/1/0 Router(config-if)#clock rate 64000 Router#show ip route
At Router r3 Router(config)#router ospf 1 Router(config-router)#network 18.104.22.168 0.255.255.255 area 0 Router(config-router)#network 22.214.171.124 0.255.255.255 area 0 Router#show ip route
3.17 LAN SWITCHING 3.17.1 SWITCH Switches are generally used to segment a large LAN smaller segments. Smaller switches such as the Cisco Catalyst 2924XL have 24 ports capable of of creating 24 different network segment for the LAN. Larger switches such as the Cisco Catalyst 6500 can have hundreds of ports. Switches can also be used to connect LANs with different media, for example, a 10 Mbps Ethernet LAN and 100 Mbps Ethernet LAN can be connected using a switch. Some switches support cut through switching, witch reduces latency and delays in the network, while bridges support only store-and-forward traffic switching. Finally switches reduce collision
on network segment . A switch is a
networking device which filters and forward packets through the network. It is a layer 2 device. It is more advanced then hub but not as advanced as router.The basic function of a switch is to manage the signal flow. When the switch is open, it allows the signal to flow through it and when it is closed, it stopes the signal to flow. Switch connects separate LAN segment. It allows multiple system to transmit simultaneously. A switch is a hardware device that filters and forward data packets between network segments. Ethernet switches are used in LAN to create Ethernet networks. Switches forward the traffic on the basis of MAC address. Switches maintain a switching table in which MAC addresses and port numbers are used to perform switching decision.
WORKING OF SWITCH When switches receives data from one of connected devices, it forward data only to the port on witch the destinated system is connected.It use the media access Control (MAC) address of the device to determine the correct port.The MAC address is a uniqe number that is programed in to every Network Interface Card(NIC). Concider, device A wants to send data to device B.When device A passes the data, switch receives it. Switch than cecks the MAC address of the destination system. It then transfer data to device B
only instead of brodcasting to all the devices. By forwarding data only to the system to witch the data is addressed, switch decreases the amount of traffic on each network link.
SWITCHING METHODS There are three types of switching method: •
Store-and-forward switching The entire frame is received and the CRC is computed and verified before
forwarding the frame. If the frame is too short (i.e. less than 64 bytes including the CRC), too long (i.e. more than 1518 bytes including the CRC), or has CRC error, it will be discarded. It has the lowest error rate but the longest latency for switching. However, for high-speed network (e.g. Fast Ethernet or Gigabit Ethernet network), the latency is not significant. It is the most commonly used switching method, and is supported by most switches. •
Cut-through switching It is also known as Fast Forward switching. A frame is forwarded as soon as the destination MAC address in the header has been received (the 1st 6 bytes following the preamble). It has the highest error rate (because a frame is forwarded without verifying the CRC and confirming there is no collision) but the shortest latency for switching
Fragment-free switching ( Modified Cut-through switching ) A frame is forwarded after the first 64 bytes of the frame have been received. Since a collision can be detected within the first 64 bytes of a frame, fragment-free switching can detect a frame corrupted by a collision and drop it.Therefore, fragment-free switching provides better error checking than cutthrough switching. The error rate of fragment-free switching is above store-and-forward switching and below cut-through switching. The latency of fragment-free
switching is shorter than store-and- forward switching and longer than cutthrough switching. NOTE: Bridges only support store-and-forward switching. Most new switch models also use store-and-forward switching. However, it should be noted that Cisco 1900 switches use fragment-free switching by default.
Types of switch based on OSI model
Layer-2 Switching Layer-2 switching is hardware based, which means it uses the MAC
address from the host NIC card to filter the network traffic. Layer-2 switch can be considered as multi- port bridge. Layer 2 switches are fast because they do not look at the network layer header information, instead it looks at the frames hardware address before deciding to either forward the frame or drop it. Limitations of Layer 2 Switching With bridge the connected networks are still one large broadcast domain. Layer 2 switch cannot break the broadcast domain, this cause performance issue which limits the size of your network. For this one reason the switch cannot completely replace routers in the internetwork.
VLAN (Virtual LAN)
VLAN provides Virtual Segmentation of Broadcast Domain in the network. The devices, which are member of same Vlan, are able to communicate with each other. The
devices of different Vlan may communicate with each other with routing. So that different Vlan devices will use different n/w addresses. Vlan provides following advantages: •
Logical Segmentation of network
Enhance network security
Creating port based Vlan In port based Vlan, first we have to create a Vlan on manageable switch then we have to add ports to the Vlan. A Virtual LAN (VLAN) is a broadcast domain created based on the functional, security, or other requirements, instead of the physical locations of the devices, on a switch or across switches. With VLANs, a switch can group different interfaces into different broadcast domains. Without VLANs, all interfaces of a switch are in the same broadcast domain; switches connected with each other are also in the same broadcast domain, unless there is a router in between. Different ports of a switch can be assigned to different VLANs. A VLAN can also span multiple switches. The advantages of implementing VLAN are •
It can group devices based on the requirements other than their physical locations.
It breaks broadcast domains and increases network throughput.
It provides better security by separating devices into different VLANs.
Since each VLAN is a separate broadcast domain, devices in different VLANs cannot listen or respond to the broadcast traffic of each other.
Inter-VLAN communication can be controlled by configuring access control lists on the router or Layer 3 switch connecting the VLANs.
Types of VLAN •
Assigning VLANs to switch ports based on the port numbers. It is easier to set up and manage. •
Dynamic VLAN Assigning VLANs to switch ports based on the MAC addresses of the
devices connected to the ports. A VLAN management application is used to set up a database of MAC addresses, and configure the switches to assign VLANs to the switch ports dynamically based on the MAC addresses of the connected devices. The application used by Cisco switches is called VLAN Management Policy Server (VMPS). Cisco switches support a separate instance of spanning tree and a separate bridge table for each VLAN.
A VLAN = A Broadcast Domain = Logical Network (Subnet)
Fig 26: VLAN Operation •
Each logical VLAN is like a separate physical bridge.
VLANs can span across multiple switches.
Trunks carry traffic for multiple VLANs.
Trunks use special encapsulation to distinguish between different VLANs.
There are two different types of links in a switched network: •
A link from Pc to switch is called as access link or A link that is part of only one VLAN. Therefore, a port connecting to an access link can be a member of only one VLAN. And the mode of port is called as access mode.
Trunk link A link from switch to switch or switch to router is called as trunk link. A 100
Mbps or 1000 Mbps point-to-point link that connects
switches or routers, and carries
frames of different VLANs . Therefore, a port connecting to a trunk link can be a member of multiple VLANs. All VLANs are configured on a trunk link by default. VLAN Trunking, by making use of frame tagging, allows traffic from different VLANs to transmit through the same Ethernet link (trunk link) across switches. VLAN Trunking identifies the VLAN from which a frame is sent by tagging the frame with the source VLAN ID (12-bit long). This feature is known as frame tagging or frame identification. When there are multiple switches then we have to use trunk links to connect one switch with other. If we are not using trunk links then we have to connect one cable from each vlan to the corresponding vlan of the other switch. With frame tagging, a switch knows which ports it should forward a broadcast frame (forward out the ports which have the same VLAN ID as the source VLAN ID). It also knows which bridge table it should use for forwarding an unicast frame (since a separate bridge table is used for each VLAN).
A frame tag is added when a frame is forwarded out to a trunk link, and is removed when the frame is forwarded out to an access link. Therefore, any device attached to an access link is unaware of its VLAN membership.
Commands to create Vlan Switch#vlan database Switch(vlan)#vlan [name ] Switch(vlan)#exit
Commands to configure ports for a Vlan By default, all ports are member of single vlan that is Vlan1. we can change vlan membership according to our requirement. Switch(config)#interface Switch(config-if)#switchport access vlan Switch(config-if)#exit
Commands to configure multiple ports in a vlan Switch(config)#interface range Switch(config-if)#switchport access vlan Switch(config-if)#exit Example: - Suppose we want to add interface fast Ethernet 0/10 to 0/18 in vlan5 Switch(config)#interface range fastethernet 0/10 – 18 Switch(config-if)#switchport access vlan 5 Switch(config-if)#exit
To display mac address table Switch#show mac-address-table Vlan
To Display Vlan and port membership Switch#show vlan brief
Command to make Trunk link Switch(config)#interface Note :- Trunk mode should not be a member of any vlan port.
126.96.36.199 Vlan Trunking Protocol (VTP) With the help of VTP, we can simplify the process of creating Vlan. In multiple switches, we can configure one switch as VTP server and all other switches will be configured as VTP client. We will create Vlans on VTP server switch. The server will send periodic updates to VTP client switches. The clients will create Vlans from the update received from the VTP server.
VTP Operation •
VTP advertisements are sent as multicast frames.
VTP servers and clients are synchronized to the latest revision number.
VTP advertisements are sent every 5 minutes or when there is a change.
VTP Modes •
VTP server mode By default all the switches in this mode are in server mode. VTP server is a
switch in which we can create, delete or modify Vlans.yhe switch in this mode forwords the vlans to next switch. The server will send periodic updates for VTP clients.
VTP client mode On VTP client, we are not able to create, modify or delete Vlans. The switch
in this mode creates the vlans that are received from server mode switch.The client will receive and forward vtp updates. The client will create same Vlans as defined in vtp update. •
VTP Transparent mode Transparent is a switch, which will receive and forward VTP update. It is able
to create, delete and modify Vlans locally. A vlan created in this mode cannot be forworded into next switch. A transparent will not send its own VTP updates and will not learn any information from received vtp update.
VTP configuration At Switch 1: •
Switch(config)#vtp mode server Switch(config)#vtp domain cisco Switch(config)#vtp password sun
At switch 2: Switch(config)#vtp mode server Switch(config)#vtp domain cisco Switch(config)#vtp password sun
At switch 3: Switch(config)#vtp mode server Switch(config)#vtp domain cisco Switch(config)#vtp password sun
Fig 27 : VTP Configuration
To see all the configurations Switch#show vtp password Switch#show vlan brief Switch#show vtp status •
Vtp reusion number
Maximum vlan supporting
Total no. of vlans
VTP Pruning Pruning is the VTP feature through which a trunk link can be automatically disable, for a particular Vlan if neighbor switch does not contain ports in that Vlan. Vlan1 is not prun eligible. •
Increases available bandwidth by reducing unnecessary flooded traffic
Example: Station A sends broadcast, and broadcast is flooded only toward
any switch with ports assigned to the red VLAN
Command to configure VTP Pruning We have to use only one command on VTP server for VTP Pruning. Switch#configure terminal Switch(config)#vtp pruning Switch(config)#exit
Fig 28 : VTP Pruning
Spanning Tree Protocol When we connect multiple switches with each other and multiple path exist from one switch to another switch then it may lead to the switching loop in the network. Multiple paths are used to create redundancy in the network. STP is only required when multiple path exist then there is possibility of loop in n/w.
Problems that occur with redundancy path (i)
Multiple copies of the frame will be received by destination.
Frequent changes in the mac address table of switch.
(iii) A mac address may appear at multiple ports in a switch. (iv)
Packets may enter in the endless loop.
Spanning Tree Protocol will solve this problem by blocking the redundancy interface. So that only one path will remain active in the switches. If the primary path goes down then disabled link will become enable and data will be transferred through that path.
Spanning Tree Protocol Basics •
Spanning Tree Protocol or STP (IEEE 802.1d) is used to solve the looping problem.It runs on bridges and switches in a network. It implements a Spanning Tree Algorithm (STA), which calculates a loop-free topology for the network.
STP ensures that there is only one active path between any two network segments by blocking the redundant paths. A redundant path is used only when the corresponding active path failed. It is not used for load-balancing.
Because STP solves the looping problem by blocking one or more links in a network, the frames traveling between some source / destination devices may not be able to use the shortest physical path.
Bridges exchange STP information using messages called Bridge Protocol Data Units (BPDUs) through Layer 2 multicast.
Wi-Fi (WIRELESS FIDELITY) The term "Wi-Fi" suggests "Wireless Fidelity", compared with the long-
established audio recording term "High Fidelity" or "Hi-Fi". The term "Wi-Fi", first used commercially in August 1999. Wi-Fi is an IEEE standard 802.11.
3.18.1 Wireless LAN Wi-Fi is also known as wireless LAN. The name of a popular wireless networking technology that uses radio waves to provide wireless high-speed Internet and network connections. "Wi-Fi works with no physical wired connection between sender and receiver by using radio frequency (RF) technology, a frequency within the electromagnetic spectrum associated with radio wave propagation. When an RF current is
supplied to an antenna, an electromagnetic field is created that then is able to propagate through space.
The Typical Range of a Wi-Fi LAN The range of a home Wi-Fi LAN depends on the wireless access point (WAP) or wireless router being used. Factors that determine a particular WAP or wireless router's range are: •
the specific 802.11 protocol employed
the overall strength of the device transmitter
the nature of obstructions and interference in the surrounding area A general rule of thumb in home networking says that 802.11b and 802.11g
WAPs and routers support a range of up to 150 feet (46 m) indoors and 300 feet (92 m) outdoors. Another rule of thumb holds that the effective range of 802.11a is approximately one-third that of 802.11b/g. Obstructions in home such as brick walls and metal frames or siding greatly can reduce the range of a Wi-Fi LAN by 25% or more. Because 802.11a employs a higher signalling frequency than 802.11b/g, 802.11a is most susceptible to obstructions. Interference from microwave ovens and other equipment also affects range. 802.11b and 802.11g are both susceptible to these.
The different wireless standards that are used for IEEE 802.11 standard are
IEEE 802.11 Standards
802.11 It was released in year 1997. The standard was original of 802.11. the max. data rate of this is 2Mbps and frequency of this is 2.4GHz and can cover upto 46m.
802.11a It was modified in year 1999. this is improved version of original standard. Operates at the frequency of 5GHz, which is less crowded than 2.4GHz where telephones and microwaves may cause interference. Although the speed is up to 54Mbps, the range is only up to 75 feet or distance covered is 46m. 802.11a standard is incompatible with both 802.11b and g because it operates at a different frequency.
802.11b This standard was released in 1999. Operates on the 2.4GHz frequency band and can transmit data at speeds of up to 11Mbps within a range of up to 100-150 feet or a distance of 90m.Wireless range can be affected by reflective or signal-blocking obstacles, such as mirrors, walls, devices and location, whether indoors or outdoors.
802.11g This standard was released in 2003. The max. data rate for the standard is 54Mbps. It supports a frequency range of 2.4GHz, covers a distance of 90m.
The latest version of IEEE 802.11 standard that is still in progress of development. The next generation of high-speed wireless networking, capable of delivering the range and capacity to support today's most bandwidth-hungry applications like streaming high definition video, voice, and music. Wireless-n is based on MIMO (Multiple Input, Multiple Output) technology, which uses multiple radios to transmit multiple streams of data over multiple channnels. Operates in two modes of frequency 2.4GHz and 5.6GHz frequency band and can transmit data at speeds of up to 11Mbps within a range of up to 100-150 feet . Wireless range can be affected by reflective or signal-blocking obstacles, such as mirrors, walls, devices and location, whether indoors or outdoors.
Wi-Fi is supported by many applications and devices
video game consoles
major operating systems
other types of consumer electronics
A common but unproductive measure to deter unauthorized users is to suppress the AP's SSID broadcast, "hiding" it. This is ineffective as a security method because the SSID is broadcast in the clear in response to a client SSID query. Another unproductive method is to only allow computers with known MAC addresses to join the network. MAC address are easily spoofed. If the eavesdropper has the ability to change his MAC address, then he may join the network by spoofing an authorized address. Wired Equivalent Privacy (WEP) encryption was designed to protect against casual snooping, but is now considered completely broken. Tools such as AirSnort or aircrack can quickly recover WEP encryption keys.
To counteract this in 2002, the Wi-Fi Alliance blessed Wi-Fi Protected Access (WPA) for wireless security. Though more secure than WEP, it has outlived its designed lifetime, has known attack vectors and is no longer recommended. In 2004 the full IEEE 802.11i (WPA2) encryption standards were released. If used with a 802.1X server or in pre-shared key mode with a strong and uncommon passphrase WPA2 is still considered secure, as of 2009.
General Conclusion Computer Networking is a very vast project in the present developing era of electronics and communication. Now a days, computers are used in a wider range. All the
organizations are using multiple computers within their departments to perform their day to day work. Computer network allows the user to share data , share folders and files with other users connected in a network. Computer Networking has bound the world in a very small area with it wide networking processes like LAN, MAN, WAN.
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