ccna

Cisco’s Market Share

40%

CISCO 60%

D-Link 3 Com Nortel Cygnus Etc..

Router is an internetworking component, that connects networks which are at different geographical locations.

Diagram of 2501 series Router Telephone

modem

Serial 1

Serial 0

AUI E0

Console AUX

V.35 modem

PC

Interfaces on a Router

1. Ethernet It is a LAN interface. Some of the models have an RJ45 port for 10baseT or 10/100. And some other have a 15 pin female connector AUI (Attachment Unit Interface). 2. Serial

It is a 60 pin female WAN interface for leased line

3. BRI/PRI It is a RJ45 WAN interface for ISDN 4. Async

It is a 37 pin female connector for dial ups.

5. Console It is a RJ45 Connector used to configure the Router for the first time. 6. Auxiliary RJ45 Connector for remote access administration.

Routers

Modular

Fixed

Modular Routers

These type of routers have up gradable slots, and the number of ports can be increased just by adding cards in the slots.

Fixed Routers These types of routers have fixed number of ports.

Cisco Router’s Series Cisco 700, 800, 1600, 1700, 2500, 2600, 3600, 4000, 5000, 7000,10000, 12000.

Fixed 700, 800,….2500

Modular 2600,….., 12000

1750 & 1751 exceptionally are Modular Routers.

Cisco’s Hierarchical Model

Access Layer 700, …, 2500

Distribution Layer 2600, …, 5000

Core Layer 7000, …, 12000

Transceiver

Internal Components of a Router

Boot ROM : It stores the mini IOS (Internet work Operating System) image (RX Boot) with extremely limited capabilities and POST routines and core level OS for maintenance.

FLASH : It is an EPROM chip that holds most of the IOS Image. It maintains everything when router is turned off. RAM : RAM holds running IOS configurations and provides caching. RAM is a volatile memory and looses its information when router is turned off. The configuration present in RAM is called Running configuration. NVRAM : It is a re-write able memory area that holds router‟s configuration file. NVRAM retains the information when ever router is rebooted. Once configuration is saved, it will be saved in NVRAM and this configuration is called Startup Configuration.

Configuration of a Router Router for the first time is configured through the CONSOLE port.COM port of a PC is connected to the console port of router with a console cable by using a transceiver. Router is accessible by a tool. In windows, it is called HYPER TEMINAL. As soon as the router is powered on and accessed, the following things happen, POST BOOT STRAP FLASH NVRAM Setup Mode

ROM (mini IOS) If IOS is Corrupted

In Setup mode, there will be a message, “Would You Like To Enter The Initial Configuration [Y/N]” :

If “Y” then, initial configuration starts. If “N” would you like to terminate the auto installation? Press “RETURN” to get started……You will land on the default prompt of the Router “ ROUTER >”.

Router>_

Working Modes Of a Router 1. User Mode (Default mode) 2. Privilege or Administrative Mode 3. Global Configuration Mode

4. Interface Configuration Mode 5. Line Configuration Mode 6. Router Mode 7. Sub-Interface Mode

USER MODE Router> is the user mode, I,e the default prompt. It means that when ever a router boots successfully it lands into the user mode. Router cannot be configured from this mode, but it is used for just monitoring purpose. Router> en Router #

PRIVILEGE MODE Router# it is the administrating mode, we can check whether the settings and configurations made have been implemented or not. E.g. “Router # Sh int e0”. If it is new router all the interfaces are by default shut down, so the message will be, “ Ethernet 0 is administratively down, line protocol is down.”

Global Configuration Mode As the name indicates, it is a global configuration mode I,e. we can configure any interface from this mode, just by entering into the interface mode. Router# Config t Router (Config)#

The “Clock” Command The clock command is used to set the clock of Router. Syntax. Router# clock set hh:mm:ss Day of week Month Year

E.g. Router#clock set 16:35:00 1 April 2003 Note* This is the only configuration which can be done from privilege mode,every other configuration should be done at global configuration mode only.

Some of the important show commands in privilege mode Router# sh clock sh int (interface name eg e0) Sh history Sh memory Sh running-config Sh startup-config To save configuration from RAM TO NVRAM Router#Copy Running-config Startup-config (or) Router#Write Memory

To configure Hostname (or) Identification of Router over the network. Router#conf t Router(config)#Hostname R_2503 Router(config)#^Z

To configure Logging banner. Router#conf t Router(config)#Banner Motd # Enter text message………….# Router(config)#^Z

Router Password Configuration 1. Previlege Password 2. Virtual Terminal Password 3. Console Password 4. Auxillary Password

Previlege PASSWORDS

Enable Password

Enable Secret

Enable Password:- It is global command restricts access to the previlege mode, the password is in clear text. Router(config)#Enable password 123 Enable Secret:-Here the password is in encrypted form. Router(config)#Enable secret cisco

Virtual Terminal Password  It establishes a login password on incoming Telnet sessions. Router#conf t

Router(config)#Line vty 0 4 Router(config-line)#password cisco Router(config-line)#login Router(config-line)#^Z

Console Password It establishes a login password on the console terminal. Router#conf t Router(config)#Line Console 0 Router(config-line)#password cisco Router(config-line)#login Router(config-line)#^Z

Auxillary Password It establishes a login password to remote administration. Router#conf t Router(config)#Line Aux 0 Router(config-line)#Login Router(config-line)#Password cisco

Router(config-line)#^Z

CONFIGURING INTERFACES LAN interface (ETHERNET Port) WAN interface (SERIAL Port)

ETHERNET Router(config)#Interface Ethernet 0 Router(config-if)#Ip Address 200.150.1.254 255.255.255.0 Router(config-if)#no shutdown Router(config-if)#^Z Router#Show Int E0

SERIAL Router(config)#Interface Serial 0 Router(config-if)#Ip Address 150.10.1.1 255.255.0.0 Router(config)#clock rate 56000 Router(Config-if)# bandwidth 64 Router(config-if)#No shutdown Router(config-if)#^Z

Interpreting The Interface Status Router# show int s0

Serial0 is up, line protocol is up. Is the messege if the interface is operational. Serial0 is up, line protocol is down….. This is if there is any connection problem. Serial0 is down, line protocol is down….. This is if there is any interface problem. Serial0 is administratively down, line protocol is down….. This is if the interface is disabled.

The “CDP”

It‟s a Cisco's proprietary protocol called the Cisco Discovery Protocol, that gives you a summary of all the directly connected Cisco devices. CDP is a L2 protocol, that discovers neighbor regardless of which protocol suite they are running. When a Cisco device boots up, the CDP is loaded by default, but can be disabled at interface level.

* The CDP is limited to the immediate neighbors only… The summary includes Device Identifier(e.g. Switch configured name or domain name), Port Identifier (e.g. Ethernet 0 and serial 0.), Capabilities list (e.g. The device can act as a source route bridge as well as a router), Platform (e.g. Cisco 2600).

CDP (Cisco’s Discovery Protocol)

Using CDP Router# sh cdp neighbor (shows neighboring devices)

Router# sh cdp entry 192.168.10.1 (shows detailed information about this perticular neighbor.) Router# sh cdp interface(shows the details of the interface of the local decive.) Router# sh cdp traffic (shows the packet sent, received, lost etc.) To disable CDP…., Router(config)#no cdp run Router(config)#int s0 Router(config-if)#no cdp enable

Backup & Restoring Routers IOS Image Using TFTP (Trivial File Transfer Protocol) TFTP Server allows you to take backup, upload and save your IOS Image and current configuration on it. TFTP is a software program of 1.3Mb. This should be installed on that TFTP server i.e., (Personnel Computer). C:\Program files\cisco systems\cisco TFTP * Note: Always while taking Backup or Restoration TFTP software should execute on that particular computer.

Backup Sources : 1. Through Telnet Session. 2. Through Console Session. 3. Through Auxillary Port (Remote Session)

Backup of IOS Image Router#Copy Flash:(Press Tab key) Tftp Address or name of the remote host [ ]? (Ip address of tftp) Destination file name [ ] ? (Press enter key or a name)

Backup of Configuration Router#Copy Startup-config Tftp Address or name of the remote host [ ]? (Ip address of tftp) Destination file name [ ] ? (Give a name)

Upgrading IOS Image Note: This process can only be done by Console Session. Router#Copy tftp Flash: Address or name of remote host []? Source file name []? Destination file name []?

Erase Flash: before copying [confirm]?

Erasing the Flash file system will remove all files: continue? [confirm] Erasing device eeeeeeee……….eeeeeee.eee.eeee.ee Loading!!!!!!!!!!!!!!!!!!!!!!!!!!!!!…….!!!!…….!!!!!!

Leased line WAN Setup Case 1: The distance between the locations is greater than 5 Km.

Requirements A pair of Routers, Leased line, pair of leased line modems V.35, Pair of G.703 Modem.

Case 2: The distance between the two locations is less than 5Km. Requirements A pair of Routers, Leased line and pair of leased line modem.

Leased line Setup( > 5km) Leased line V.35 modem

V.35 modem V.35 Cable

G.703

G.703

Csu/ Dsu

Mux/ Mux/ Dmux S0 Dmux Csu – channel service unit S0 Dsu – data service unit E0 E0 S0 – Serial port of router E0 – Ethernet port of a router Router Switch/hub Switch/hub Internal Network

Internal Network

Leased line Setup (< 5 km) V.35 modem V.35 Cable

Leased line V.35 modem

Csu/ Dsu

S0

E0 Switch/hub Internal Network

S0

Telephone Exchange

Router

E0 Switch/hub

Internal Network

Routing Routing is of three types. • Static • Dynamic and • Default When the destination is known, static and dynamic routing is done. For unknown destinations, default routing is employed. In dynamic routing, the path is fixed by the protocol. The paths will be changing depending on the length of the path. Always the shortest path is preferred. Static routing is done by the users. These paths are stored in the routing table.

Example: 10.0.0.1/8 S0

10.0.0.2/8

S0 E 0 192.168.1.150/24

Switch/hub 192.168.1.0/24 Location A

E 0 192.168.2.150/24

Switch/hub 192.168.2.0/24 Location B

Router(config)# ip routing Router# sh ip route (it shows all the directly connected networks). “ C 192.168.1.0/24 directly connected to E0” “ C 10.0.0.0/8

“

„

„

„

S0”

“ C “ indicates connected networks. Static Routing Syntax

Router(config)# ip route (dest-network) (subnet mask) (next hop address)

Location A

Router(config)# ip routing Router(config)# ip route 192.168.2.0 255.255.255.0 10.0.0.2 Note* if we don’t know the address of next hop, we can just write the name of the hop. Router(config)# ip route 192.168.2.0 255.255.255.0 S0

Location B Router(config)# ip routing Router(config)# ip route 192.168.1.0 255.255.255.0 10.0.0.1

Router# sh ip route

C 192.168.1.0/24 directly connected to E0 C 10.0.0.0/8

“

„

“

“ S0

S 192.168.2.0/24 [1/0] via 10.0.0.2 •“S” represents static. [a/b] ~ [1/0], here a=1 is the administrative distance value and b has no significance in static routing. For static and default routing b can be 0 or 1. • the lesser the administrative distance value, higher the preference.

“Tracert”, “Trace Route” and “Route print”. C:\> tracert C:\> route print Router# trace route (gives the complete route) Router# sh arp (to check MAC addresses)

Default Routing Router(config)# ip routing Router(config)#ip route DA (S/N mask next) (next hop address) Router(config)# ip route 0.0.0.0 0.0.0.0 s1

Router# sh ip route

C 192.168.1.0/24 directly connected to E0 C 10.0.0.0/8

“

“

to S0

S* 0.0.0.0/0

“

“

to S0

Dynamic Routing It is a type of routing where routing protocols( eg. RIP and IGRP) are used between routers to determine the path and maintain routing table. Once the path is determined a router can route a routed protocol(IP). Dynamic routing uses broad casts and multicasts to communicate with other routers. The routing metric helps routers find the best path to each network.

Classification Of Routing Protocols  Distance Vector  Hybrid Routing  Link State

Distance Vector: the distance vector approach determines the direction and the distance to any link in the internetwork. When the topology in a distance vector routing protocol changes, routing table updates in the router must occur. This update process proceeds step-by-step router to router. Eg. RIP and IGRP. Link State : it recreates the exact topology of the entire network(atleast the partion of the network where the router is situated). Eg . OSPF.

Hybrid Routing : it combines aspects of the link state and the distance vector algorithm.

Functions of a distance vector routing protocol.  Identification of source of information  Discovering routes  Select the best route  Maintain Route information

Enabling RIP Configuration Note: • Maximum 6 paths (Default 4). •“Hop count metric” selects the path • Route updates are broadcast for every 30 seconds. Router(config)# router rip Router(config-router)# network (network ip)

Router# sh ip protocol (shows the current routing protocol) Router# sh ip route

172.16.1.0 10.1.1.1 10.2.2.2 E0 S2 S2 S3 S3 10.1.1.2 10.2.2.3 172.16.1.1

192.168.1.0 E0

192.168.1.1

Router rip Network 172.16.0.0

Network 10.0.0.0

Router rip Network 10.0.0.0

Router rip

Network 192.168.1.0 Network 10.0.0.0

Autonomous Systems An autonomous system is a collection of networks under a common administrative domain. IGPs operate within an autonomous system where as EGP connects different autonomous systems. Every autonomous system has a distinct number.The Internet Assigned Numbers Authority (IANA) is responsible for allocating this number. Eg. Autonomous system 100. We can use any number unless the organization plans for an EGP.

Configuring IGRP Syntaxes. Router(config)#router igrp autonomous number

This defines IGRP as the routing protocol. Router(config-router)#Network network-ip Selects directly connected networks. Router(config-router)#variance multiplier Configures unequal-cost load balancing by defining difference between the best metric and the worst acceptable metric. Router(config-router)#traffic-share (balanced/ min)

Autonomous System 100 172.16.1.0 10.1.1.1 10.2.2.2 E0 S2 S2 S3 S3 10.1.1.2 10.2.2.3 172.16.1.1

192.168.1.0 E0

192.168.1.1

Router igrp 100 Network 172.16.0.0 Network 10.0.0.0

Router igrp 100 Network 10.0.0.0

Router igrp 100

Network 192.168.1.0 Network 10.0.0.0

IP Classless Command Router(config)# ip classless

A router by default assumes that all the subnets of a directly connected network should be present in the routing table. If a packet is received with a destination address, of an unknown subnet of directly attached network, the router assumes that the subnet does not exists and drops the packet. This happens even if routing table has a default route.For the above condition if IP Classless is configured, and if any packet is received, then the router will match it to the default route and forword it to the next hop specified by the default route.

EIGRP

Calculation of Wildcard Mask WCM = BCM-SNM 1. 192.168.1.0/24

255.255.255.255 - 255.255.255. 0 0 . 0 . 0 .255 2. 192.168.1.0/27 255.255.255.255

- 255.255.255.224 0 . 0 . 0 . 31 3. 192.160.1.10

0.0.0.0

OSPF OSPF(Open Short Path First) is of two types : 1) Single Area OSPF and 2) Multi Area OSPF.

Area0

S0

Area2

S0 IR ABR

ABR

Internal Routers IR

Area1

Area Border Router

OSPF under Single Area

S 0 192.168.1.194/252

Router A E 0 1.33 192.168.1.32/ 255.255.255.224

192.168.1.193/252 S 0

Router B E 0 1.65 192.168.1.64/ 255.255.255.224

(Config)# ip routing (Config-Router)# router OSPF 6573 (Config-Router)# network 192.168.1.32 0.0.0.31 area 1 (Config-Router)# area 1 range 192.168.1.32 255.255.255.224 (Config-Router)# network 192.168.1.192 0.0.0.3 area 1 (Config-Router)# area 1 range 192.168.1.192 255.255.255.224

Configuration of Router B --------------------------------

(Config)# ip routing (Config-Router)# router OSPF 6573 (Config-Router)# network 192.168.1.32 0.0.0.31 area 1 (Config-Router)# area 1 range 192.168.1.64 255.255.255.224 (Config-Router)# network 192.168.1.195 0.0.0.3 area 1 (Config-Router)# area 1 range 192.168.1.195 255.255.255.252

OSPF under Different Areas

Area 0

Area 2

Area 1

192.168.1.0

Router A

Router B

E0

E0

1.50

5.50

192.168.5.0

Configuration of Router A -------------------------------(Config)# ip routing (Config-Router)# router OSPF 6573 (Config-Router)# network 192.168.1.0 0.0.0.255 area 1 (Config-Router)# area 1 range 192.168.1.0 255.255.255.0 (Config-Router)# network 172.16.0.0 0.0.255.255 area 0 (Config-Router)# area 0 range 172.16.0.0 255.255.0.0

Configuration of Router B --------------------------------

(Config)# ip routing (Config-Router)# router OSPF 6573 (Config-Router)# network 192.168.5.0 0.0.0.255 area 2 (Config-Router)# area 2 range 192.168.5.0 255.255.255.0 (Config-Router)# network 172.16.0.0 0.0.255.255 area 0 (Config-Router)# area 0 range 172.16.0.0 255.255.0.0

Access Control List It is also called Network Traffic Control Management (NTCM). We can provide restrictions to individual users, subnets and services etc.

ACL Standard ACL

Extended ACL

Any access list is identified by its number.

S. A. L

1 – 99

Ex. A. L

100 - 199

Rules for creating and implementing Access List 1. Access list must begin with the Deny Statements (If exists) then Permit Statements must follow. 2. There must be at least one Permit Statement as an Implicit “Deny All” always exists. 3. While Implementation of Access list, There must be only one Access list per Interface, per direction and per protocol.

Standard Access List S 0 172.16.1.1 Router A

E 0 1.50 1.4 1.3

172.16.1.2 S 0 Router B

E 0 5.50 5.4

5.1

5.3

5.2

1.1 1.2

Syntax Router(config)# Access-list ALNO P/D Src

Src-WCM

Router(config)# Int Router(Config-if)#Ip Access-Group

Configuration Standard Access-list For Router A Restricting particular user (Config)# Access-list 1 deny 192.168.1.3 0.0.0.0 (Config)# Access-list 1 permit 0.0.0.0 255.255.255.255 or Access-list 1 permit any Restricting a Network (Config)# Access-list 1 deny 192.168.3.0 0.0.0.255 (Config)# Access-list 1 permit any

Extended Access List

S 0 172.16.1.1

Router A E 0 1.50

172.16.1.2 S 0

Router B E 0 5.50

1.4

1.1

5.4

5.1

1.3

1.2

5.3

5.2

1.20

Configuration of Router A (Config)# Access-list 101 deny TCP 192.168.5.0 0.0.0.255 192.168.1.20 0.0.0.0 eq FTP (Config)# Access-list 101 permit IP any any

Implementation (Config)#int E0

(config-if)# IP Access-group 101 Out

NAT(Network Address Translation)

S 0 172.16.1.1

Router A E 0 1.50 1.4 192.168.1.3

172.16.1.2 S 0

Router B E 0 5.50

1.1

5.4

5.1

1.2

5.3

5.2

Note : 192.168.1.3 is denied from entering the network of 5.0.So it will enter with mask.

Configuration of Router A -------------------------------# Config t (Config)# int E 0 (Config-if)# ip address 192.168.1.50 255.255.255.0 (Config-if)# no shut (Config-if)# exit (Config)# int S 0 (Config-if)# ip address 172.16.1.1 255.255.0.0 (Config-if)# clock rate 56000 (Config-if)# bandwidth 64 (Config-if)# no shut (Config-if)# exit (Config)# ip routing (Config-Router)# ip route 192.168.5.0 255.255.255.0 172.16.1.2 (Config)# int E 0 (Config-if)# ip nat inside

(Config)# int S 0 (Config-if)# ip nat outside (Config)# access-list 1 permit 192.168.1.3 0.0.0.0 (Config)# ip nat inside source list 1 int S 0 overload

Configuration of Router B -------------------------------# Config t (Config)# int E 0 (Config-if)# ip address 192.168.5.50 255.255.255.0 (Config-if)# no shut (Config-if)# exit (Config)# int S 0 (Config-if)# ip address 172.16.1.2 255.255.0.0 (Config-if)# clock rate 56000 (Config-if)# bandwidth 64 (Config-if)# no shut (Config-if)# exit

(Config)# ip routing (Config-Router)# ip route 192.168.1.0 255.255.255.0 172.16.1.1 (Config)# access-list 10 deny 192.168.1.3 0.0.0.0 (Config)# access-list 10 permit any

(Config)# int E 0 (Config-if)# ip access-group 10 out

Note : Only Public IP can go to the Internetworking world.

A Scenario of providing Net access to the IP's of Router B

172.16.1.1

172.16.1.2

Routing 1.50

Router A

5.50 Routing

Switch

Leased line

192.168.1.99

Natting

Router B 5.0

Configuration of Router A -------------------------------# Config t (Config)# int E 0 (Config-if)# ip address 192.168.1.50 255.255.255.0 (Config-if)# no shut (Config-if)# exit (Config)# int S 0 (Config-if)# ip address 172.16.1.1 255.255.0.0 (Config-if)# clock rate 56000(for DCE) (Config-if)# bandwidth 64 (Config-if)# no shut (Config-if)# exit

(Config)# ip routing (Config-Router)# ip route 0.0.0.0 0.0.0.0 192.168.1.99

(Config)# int E 0 (Config-if)# ip nat outside (Config-if)# no shut (Config-if)# exit (Config)# int S 0 (Config-if)# ip nat inside ((Config-if)# exit (Config)# access-list 10 permit 172.16.0.0 0.0.255.255 (Config)# ip nat inside source list 10 int E 0 overload

Configuration of Router B -------------------------------# Config t (Config)# int E 0 (Config-if)# ip address 192.168.5.50 255.255.255.0 (Config-if)# no shut (Config-if)# exit

(Config)# int S 0 (Config-if)# ip address 172.16.1.2 255.255.0.0 (Config-if)# clock rate 56000 (Config-if)# bandwidth 64 (Config-if)# no shut (Config-if)# exit (Config)# int E 0 (Config-if)# ip nat inside (Config-if)# no shut (Config-if)# exit (Config)# int S 0 (Config-if)# ip nat outside (Config-if)# exit (Config)# ip routing (Config-Router)# ip route 0.0.0.0 0.0.0.0 172.16.1.1 (Config)# access-list 10 permit 192.168.5.0 0.0.0.255 (Config)# ip nat inside source list 10 int E 0 overload

PPP(Point-to-Point) using PAP protocol

Internet based leased line S 0 172.16.1.1

Router A (ISDN) E 0 1.50

172.16.1.2 S 0

Router B (Zoom) E 0 5.50

1.4

1.1

5.4

5.1

1.3

1.2

5.3

5.2

NOTE : Passwords of both should be same.

Configuration of Router A -------------------------------# Config t (Config)# int E 0 (Config-if)# ip address 192.168.1.50 255.255.255.0 (Config-if)# no shut (Config-if)# exit (Config)# int S 0 (Config-if)# ip address 172.16.1.1 255.255.0.0 (Config-if)# clock rate 56000(for DCE) (Config-if)# bandwidth 64 (Config-if)# no shut (Config-if)# exit (Config)# ip routing (Config-Router)# ip route 192.168.5.0 255.255.255.0 172.16.1.2 (Config)# int S 0 (Config-if)# encapsulation ppp (Config-if)# ppp authentication PAP (Config-if)# ppp PAP sent-username zoom password cisco

Configuration of Router B -------------------------------# Config t (Config)# int E 0 (Config-if)# ip address 192.168.5.50 255.255.255.0 (Config-if)# no shut (Config-if)# exit (Config)# int S 0 (Config-if)# ip address 172.16.1.2 255.255.0.0 (Config-if)# clock rate 56000(for DCE) (Config-if)# bandwidth 64 (Config-if)# no shut (Config-if)# exit (Config)# ip routing (Config-Router)# ip route 192.168.1.0 255.255.255.0 172.16.1.1 (Config)# int S 0 (Config-if)# encapsulation ppp (Config-if)# ppp authentication PAP (Config-if)# ppp PAP sent-username ISP password cisco

PPP(Point-to-Point) using CHAP protocol

Internet based leased line S 0 172.16.1.1

Router A (ISDN) E 0 1.50

172.16.1.2 S 0

Router B (Zoom) E 0 5.50

1.4

1.1

5.4

5.1

1.3

1.2

5.3

5.2

NOTE : Passwords of both should be same.

Configuration of Router A -------------------------------# Config t (Config)# int E 0 (Config-if)# ip address 192.168.1.50 255.255.255.0 (Config-if)# no shut (Config-if)# exit (Config)# int S 0 (Config-if)# ip address 172.16.1.1 255.255.0.0 (Config-if)# clock rate 56000(for DCE) (Config-if)# bandwidth 64 (Config-if)# no shut (Config-if)# exit (Config)# ip routing (Config-Router)# ip route 192.168.5.0 255.255.255.0 172.16.1.2 (Config)# int S 0 (Config-if)# encapsulation ppp (Config-if)# ppp authentication CHAP (Config-if)# ppp CHAP hostname zoom (Config-if)# ppp CHAP password cisco

Configuration of Router B -------------------------------# Config t (Config)# int E 0 (Config-if)# ip address 192.168.5.50 255.255.255.0 (Config-if)# no shut (Config-if)# exit (Config)# int S 0 (Config-if)# ip address 172.16.1.2 255.255.0.0 (Config-if)# clock rate 56000(for DCE) (Config-if)# bandwidth 64 (Config-if)# no shut (Config-if)# exit (Config)# ip routing (Config-Router)# ip route 192.168.1.0 255.255.255.0 172.16.1.1 (Config)# int S 0 (Config-if)# encapsulation ppp (Config-if)# ppp authentication CHAP (Config-if)# ppp CHAP hostname ISP (Config-if)# ppp CHAP password cisco

DDR(Dial on Demand Routing) ISP

S 0 172.16.1.1

172.16.1.2 S 0

Router A E 0 1.50

Router B E 0 5.50

1.4

1.1

5.4

5.1

1.3

1.2

5.3

5.2

# Config t (Config)# isdn switch-type basic-net 3 (Config)# int E 0/1 (Config-if)# ip address 192.168.1.50 255.255.255.0 (Config-if)# no shut (Config-if)# exit (Config)# int Bri 1/0 (Config-if)# no ip address (Config-if)# encapsulation ppp (Config-if)# no cdp enable (Config-if)# no shut (Config-if)# exit (Config)# int dialer 1 (Config-if)# ip address negotiated (Config-if)# encapsulation ppp (Config-if)# no cdp enable (Config-if)# ppp authentication CHAP PAP callin (Config-if)# ppp CHAP hostname unicomin@hd2 (Config-if)# ppp CHAP password password

(Config-if)# ppp PAP sent-username unicomin@hd2 password password (Config-if)# dialer in-band (Config-if)# dialer string 3328400 (Config-if)# dialer idle-time out 180 (Config-if)# dialer hold-queue 10 (Config-if)# exit (Config)# access-list 1 permit 192.168.1.0 0.0.0.255 (Config)# dialer-list 1 protocol ip permit ((Config)# int bri 1/0 (Config-if)# dialer rotary-group 1 (Config-if)# no shut (Config-if)# exit (Config)# int dialer 1 (Config-if)# dialer-group 1 (Config-if)# exit (Config)# ip routing (Config-router)# ip route 0.0.0.0 0.0.0.0 dialer 1 2

(Config)# ip name-server 202.54.30.2 (Config)# ip name-server 202.54.2.30 (Config)# int E 0 (Config-if)# ip nat inside (Config-if)# no shut (Config-if)# exit (Config)# int Bri 1/0 (Config-if)# ip nat outside (Config-if)# no shut (Config-if)# exit (Config)# int dialer 1 (Config-if)# ip nat outside (Config-if)# exit (Config)# ip nat inside source list 1 int dialer 1 overload

Backup Interface for a Leased Line

ISP

S 0 172.16.1.1

172.16.1.2 S 0

Bri 0 CPE/DTE

ISP E 0 1.50

E 0 5.50

1.4

1.1

5.4

5.1

1.3

1.2

5.3

5.2

CPE -Customer Premises Equipment DTE -Data Communications & Circutary end

# Config t (Config)# isdn switch-type basic-net 3 (Config)# int E 0/1 (Config-if)# ip address 192.168.1.50 255.255.255.0 (Config-if)# no shut (Config-if)# exit (Config)# int S 0 (Config-if)# ip address 172.16.1.1 255.255.0.0

(Config)# int Bri 1/ 0 (Config-if)# no ip address (Config-if)# encapsulation ppp (Config-if)# no cdp enable (Config-if)# no shut (Config-if)# exit

(Config)# int dialer 1 (Config-if)# ip address negotiated (Config-if)# encapsulation ppp (Config-if)# no cdp enable (Config-if)# ppp authentication CHAP PAP callin (Config-if)# ppp CHAP hostname zoom (Config-if)# ppp CHAP password cisco (Config-if)# ppp PAP sent-username isp password cisco (Config-if)# dialer in-band (Config-if)# dialer string 3328400 (Config-if)# dialer ideal-time out 180 (Config-if)# dialer hold-queue 10 (Config-if)# exit (Config)# access-list 1 permit 192.168.1.0 0.0.0.255 (Config)# dialer-list 1 protocol ip permit ((Config)# int bri 1/ 0 (Config-if)# dialer rotary-group 1 (Config-if)# no shut (Config-if)# exit

(Config)# int dialer 1 (Config-if)# dialer-group 1 (Config-if)# exit (Config)# ip routing (Config-router)# ip route 0.0.0.0 0.0.0.0 S 0 (Config-router)# ip route 0.0.0.0 0.0.0.0 dialer 1 2 (Config)# ip name-server 202.54.30.1 (Config)# ip name-server 202.54.1.30 (Config)# int E 0 (Config-if)# ip nat inside (Config-if)# no shut (Config-if)# exit (Config)# int Bri 1/ 0 (Config-if)# ip nat outside (Config-if)# no shut (Config-if)# exit

(Config)# int dialer 1 (Config-if)# ip nat outside (Config-if)# exit (Config)# Access-list 2 permit 4 public 10 (Config)# ip nat inside source list 2 int dialer 1 overload (Config)# int S 0 (Config-if)# backup interface bri 1/0 (Config-if)# backup delay 30 60

Frame Relay Point - to - Point frame-relay Network

Router A

S 0 172.16.1.1 Dlci 101

E 0 1.50

PVC Fr-Switch

172.16.1.2 S 0 Router B Dlci 102

Fr-Switch

E 0 5.50

1.4

1.1

5.4

5.1

1.3

1.2

5.3

5.2

Config t (Config)# int S 0 (Config-if)# no ip address (Config-if)# encapsulation frame-relay (Config-if)# no shut (Config-if)# exit (Config)# int S 0.1 point-to-point (Config-if)# bandwidth 64 (Config-if)# ip address 172.16.1.1 255.255.0.0 (Config-if)# frame-relay interface DLC1 102 (or) (Config-if)# frame-relay map ip 172.16.1.2 102 broadcast (Config-if)# no shut (Config-if)# exit

(Config)# ip routing (Config)# ip route 192.168.5.0 255.255.255.0 172.16.1.2

Point - to - Multi Point

4.0 10.0.0.1

D 1.0

10.0.0.4

10.0.0.2

103 104

102

A

C 101

B

10.0.0.3

2.0

3.0

Configuration of Router A -------------------------------Config t (Config)# int S 0 (Config-if)# no ip address (Config-if)# encapsulation frame-relay (Config-if)# no shut (Config-if)# exit (Config)# int S 0.1 multipoint (Config-if)# bandwidth 64 (Config-if)# ip address 10.0.0.4 255.0.0.0 (Config-if)# frame-relay map ip 10.0.0.1 103 broadcast (Config-if)# frame-relay map ip 10.0.0.2 102 broadcast (Config-if)# frame-relay map ip 10.0.0.3 101 broadcast (Config-if)# no shut (Config-if)# exit (Config)# ip routing (Config)# ip route 192.168.2.0 255.255.255.0 10.0.0.3 (Config)# ip route 192.168.4.0 255.255.255.0 10.0.0.1 (Config)# ip route 192.168.5.0 255.255.255.0 10.0.0.2

Point-to-Point - Point-to-Point

4.0

172.16.1.2

1.0 172.16.1.1

10.0.0.2

103

104

102

10.0.0.1 161.16.1.1

101

10.0.0.3

2.0

3.0

Configuration of Router A -------------------------------Config t (Config)# int S 0 (Config-if)# no ip address (Config-if)# encapsulation frame-relay (Config-if)# no shut (Config-if)# exit (Config)# int S 0.1 point-to-point (Config-if)# bandwidth 64 (Config-if)# clockrate 56000 (Config-if)# ip address 172.16.1.1 255.255.0.0 (Config-if)# frame-relay map ip 172.16.1.2 103 broadcast (Config-if)# no shut (Config-if)# exit

(Config)# int S 0.2 point-to-point (Config-if)# ip address 161.16.1.1 255.255.0.0 (Config-if)# no shut (Config-if)# bandwidth 64 (Config-if)# clock rate 56000 (Config-if)# frame-relay map ip 161.16.1.2 102 broadcast (Config-if)# exit (Config)# int S 0.3 point-to-point (Config-if)# bandwidth 64 (Config-if)# clockrate 56000 (Config-if)# ip address 10.0.0.1 255.0.0.0 (Config-if)# frame-relay map ip 10.0.0.2 101 broadcast (Config-if)# no shut (Config-if)# exit

(Config)# ip routing (Config)# ip route 172.16.0.0 255.255.0.0

Iso International organization for standardization Iso has designed a reference model called osi reference model (open system interconnection). It has 7 layers. It says that Any n/w for comunication needs 7 layers 1. Application layer The user uses application layer to send the data. The protocols @ this layer are ftp,http,smtp(e-mail) telenet etc. 2. Presentation layer Presentation layer takes the data from application layer and present In different formats for securing reason. The services offered @ This layer are Compression – decompression Coding – decoding Encryption - decryption

3. Session layer Establishing the session or the conectivity n/w n/w 1 & n/w 2 is done By the session layer. It 1. Establishes a session 2. maintains it & 3. Terminates it b/w the application 4. Transport layer End-end connectivity during a session b/w two application is done By the transport layer. It also decides the type of connection like tcp or udp i.e. connection oriented or connection less. Services: Sequencing Flow ctrl, error detection & correction Transport layer info + data is called segment.

5. Netwrok layer Logical addressing is done at thenetwork layer i.e. source address & destination address are attached to the data. Protocols @network layer Routed protocols Eg: ip,ipx

routing protocols eg: rip,igrp,ospf

Routed protocols: they always carry the data along with them Routing protocol: they identify the path for routed protocol to carry the data At this layer routers & layer 3 switches forms packets.

Data link layer MAC Media access control data

LLC logical link control framing of

Ip address is lik the pincode & MAC address is like house number. Here layer2 switches are used. Wab protocols used at this layer are PPP,HDLC,FP,X.25 etc. Here error checking CRC bits are added to the packets DLL info+ packets --> frames

7 physical layer Takes care of physical connectivity i.e connector,cable etc. here Frames are converted to bits (1‟s & 0‟s). The devices like hubs, repeaters,cables & connectors are used at this layer.

I P Addressing Now a days ip ver4 is followed. It is a 32-bit addressing scheme. 32bits are divided into 4 octets of 8 bits each. i.e 8-8-8-8. i.e (1‟s & 0‟s)-(1‟s & 0s)-(1‟s & 0‟s)-(1‟s & 0‟s). (binary format). The ip address is maximum of 255 & min of 0. In future ip ver 6 is expected. It is 128 bit scheme. Ip adresses are clsassified into different classes.

Class Class Class Class Class

A B C D E

0 128 192 224 240

-

127 191 223 239 255

8-8-8-8 M.S.O Most Significant Ocate considering MSO

Through out class A, the MSB „0‟ is constant in class B the Msbs are „101‟ constant through out. Class D & E are not used for internetworking class D is used for Multicast network. “ E “ “ “ research. class A 0-0-0-0 should not be assigned for any divice 127-0-0-0 is reserved for loopback 127-0-0-1 127-0-0-” 127-0-0-” usually reserved for loopback 127-0-0-” 127-255-255-254

Hence 0 & 127 cannot be used for adressing so actual range will be 1 to 126. All ip addresses are divided into two. 1.network I.d 2.host I.d in class a address there is 1n\w I.d postion & 3 host I.d postion I,e N-H-H-H.. Class A N-H-H-H Class B N-N-H-H Class C N-N-N-H

Network Ids are represented by 1s & host ids are by 0s.

Types of ip adresses IP address

public ip address

private ip address

Public network: the public address is defined with routing over the Internet it is given by I.S.P & routing table is created on the internet. Private network: for internal network I,e intranet, all the ip addresses Are governed by a body called INTERNIC. If we are a part of asia Pacefic then it is governed by APNIC. We can run our private network with any ip addresses of our choice But it should not be connected to internet.

Range of addresses for private network Class A 10.0.0.0 to 10.255.255.255 Class B 172.16.0.0 to 172.31.255.255 Class C 192.168.0.0 to 192.168.255.255 Private ip addresses donot have routing. To meet the demand of no.of networks, the network is broken Into smaller networks called subnets. Eg: find no.of subnets, hosts/s.n subnet mask & valid ip addresses For a class c address. 192.168.1.0/24 „24‟ shows the network bits 24= 3 octate position bits are enough, therefore no need to borrow Any bits from host position. =24 network & no host Default subet mask is 255.255.255.0 & valid ip addresses are 192.168.1.0 network

Switch An essential component of lan. Switches are of different types like Layer 2 layer 3, layer 4, layer 5….. Layer 2 switch : Switch hub •Layer 2 layer 1 •b.w is equal @ all ports b.w is shared •Identifies source with MAC cannot identifiy the source •Broad cast occur, till mac table alwaysbroad cast Is built •Collision occur when both A&B Many collisions Wants to reach D. •1 broad cast domain 4 collision 1 broad cast domain 1 collision Domains domain

Switches

Access layer

Distribution layer

Core layer

Access layer swithc: catalyst 1912 Catalyst – manufacturer, but it is now owned by cisco. 12 port switch

Switch standard edition

enterprise edition

To configure VLANS,go for enterprose edition as standard edition Will not support VLAN. For uplinking or cascading 100mbps is minimum required. Functions of switch 1. Adress learning 2. Filter & forwarding 3. Loop avoidance 1. Address learning Booting 1.blocking state (15 secs) 2.Listening state (15 secs) 3.Learning stage (20 secs) 4.Forwarding stage (20 secs)

The switch will always learn the MAC address from the source itself The source should atleast communicate once to learn the MAC address 2. Filter & forwarding : store & forward cut through fragment free On access layer the default is fragment free we can change to any Of the3 mentioned above. 1.store & forward: it stores the whole information (1500 bytes Ethernet) into buffer, then checks for errors, looks for destination In MAC table and then forward. 2. Cut through: no error checking.as soon as a packet arrives It looks into MAC table & forward.

3.loop avridance: consider a seenario whr pci wants to communicate To pc2. Switch a makes entry of pc1 in its MAC table as it is a new Switch. This looping is before the mac table I s made. This is called Initial flood or broad cast storm. STP: spanning tree protocol. To avoid loops in case of a cascaded Switch stp is enabled by default. Parameters to select a switch 1. Bridge priority (32768) default.(1-655355) 2. MAC address Bridge id is calculated. Bridge id=bridge priority + mac address. Which ever the switch having least bridge ID will be elcted as root Bridge and others are non-root bridge. On root bridge the ports used For cascading are called designated ports. All the designated ports Will be at forwadingf state . In non root bridge from the two ports one will be selected as root port. This will be depending on the cost speed).least cost path (faster transmission) the other port will be blocked.

The “hello” packets that are sent by root bridge for every 2 sec to inform that it is working properly are called BPDUS; (bridge protocol data limits). If non root bridge do no receive 10 BPDUs for next 20secs then it is clear that the root bridge has Failed. 20secs – max age time Then a new root bridge is selected. In the above eg:if switch A is selected as root bridge and ports A & B Of switch A are designated ports. Depending on the shortest paths For high speed & low cost one port of switch B is selected as root port & the other will be blocked.

ISDN Integreted services digital network. It is a circuit switching technology approved by CCITT. ISDN PSTN •Digital analog •More bandwidth less •Multiple services like, •Voice,data,video etc. ISDN BRI PRI (Basic rate interface 2b channels & id chennel) european standard north american standard 30 bchannels 23 bchannels & & id channel id channel

„B‟channel – it is a bearer channel for data. „D‟channel – it is a delta channel for synchronization In bri each B channel = 64 kbps d channel = 16kbps Max 128 kbps BW in isdn In PRI both B & D channels _= 64kbps. European – 2mbps North american – 1.54 mbps ISDN will have a voltage of 90-110v

SPID number : (service profile identifier) to identify the link. Types of ISDN switches Euro-basic net3 U.S-basic 5 ess-at&t standard U.K-basic net3 & basic net5 France-vn3 & vn4 Ss7 (signalling system7) Will be configured at the back bone side. telco vn3/vn4 France

ss7

basic net3 India

E-series, I-series & Q-series E-tells about telephone network & ISDN network I-tells about concepts & interfaces of ISDN Q-tells about signalling & switching of ISDN DDR Dail on Demand Routing The main feature of ISDN is it dials & connects on request & Discounects when no data transfer is taking place. nat (network address translation IP NAT inside IP NAT out side overload

IPNAT inside: any request from th internal network will be NATED To public Ip address sending the request from internal network To Bri interface is overloading. When ever NAT is enable, the router will maintain a nat table. Nat table:

When nat t able is enabled nau request will be allocated a port Number after 1024. Above 1024 port numbers are reserved for other Services. This allocation of port numbers is dynamic.

Configuring a DDR for ISDN Config#int e0 Config#ip adress 192.168.5.150 255.255.255.0 Config#ip nat inside Config#exit Config-if#int bri 0 Config-if#ip address negotiated Config-if#encapsulation PPP Config-if#PPP authenticaiton PAP chap collin Config-if#PPP chap hostname (username) Config-if#PPP chap password (password) Config-if#dialer string (tel.no.) Config-if#dialer idle timeout (time in secs) Config-if#dialer group Config-if#ip nat outside Config-if#exit

Ip address negotialted : this is when an ip adress is fetched kdynamicall From ISP 7 donot have a permanent public I.P adress Dialer – list range 1-10 to configure router as a DHCP server Config#ip pool staring ip end ip. Some ISDN command Sh int bri0 Sh isdn status (layer 1 should be active. If not physical conectivity is lost) Sh isdn active Sh isdn history Sh ip network translaiton