Ccna Notes
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Contents SL No.
TOPICS
PAGE No.
1
Command Line Interface
2
2
Static Routing
5
3
Wan Protocols
10
4
RIP and IGRP Protocols
14
5
TELNET
21
6
– Security SDM – SDM Security Device Manager
24
7
ACL- Access Control List
27
8
NAT – Network NAT – Network Address Translation
31
9
OSPF and EIGRP
35
10
RIP V2
43
11
Frame relay
50
12
Switching
59
13
Intervlan
63
14
Virtual Private Network
69
15
Internet Protocol Version 6
71
16
Wireless LAN
79
17
Booting
81
COMMAND LINE INTERFACE (CLI)
To enter the hyper terminal Programs Accessories Communication HyperTerminal (HyperTerminal window opens) -prompts for the screen name (not the router name) Michael Odongo short notes -1-
-connect to window select com1 ok -com1 properties window select restore default ok
Switch ON the router (if new router that is not configured it will ask ----Would u like to enter initial configuration dialog[yes/no]: no Press return to get started (enter) Router> * User Mode/User Mode/User Executable Mode Mode Router> enable (enter) Router# * Privileged Mode/Enable Mode – Executable Mode. The following commands can be executed in this mode Router#show running-config(enter) Router#debug xxx Router#copy xxx Router#configure Router#configure terminal(enter) Router(config)# * Global Configuration Mode - Any configuration change in this mode affects the t he whole router. Router(config)#interface Router(config)#interface e 0/fastethernet 0/fastethernet 0/ S0 / S 1(enter) Router(config-if)# * Specific Configuration Mode – configuration changes changes to specific part of the router like lines and interfaces.
Setting User mode Password Router(config)#Line Router(config)#Line console 0(enter) 0(enter) Router(config-line)#password Router(config-line)#password xxxx Router(config-line)#login Router(config-line)#login
To set username & password for the user mode Router(config)#username Router(config)#username xxxx password xxxx Router(config)#Line Router(config)#Line console 0 -2-
-connect to window select com1 ok -com1 properties window select restore default ok
Switch ON the router (if new router that is not configured it will ask ----Would u like to enter initial configuration dialog[yes/no]: no Press return to get started (enter) Router> * User Mode/User Mode/User Executable Mode Mode Router> enable (enter) Router# * Privileged Mode/Enable Mode – Executable Mode. The following commands can be executed in this mode Router#show running-config(enter) Router#debug xxx Router#copy xxx Router#configure Router#configure terminal(enter) Router(config)# * Global Configuration Mode - Any configuration change in this mode affects the t he whole router. Router(config)#interface Router(config)#interface e 0/fastethernet 0/fastethernet 0/ S0 / S 1(enter) Router(config-if)# * Specific Configuration Mode – configuration changes changes to specific part of the router like lines and interfaces.
Setting User mode Password Router(config)#Line Router(config)#Line console 0(enter) 0(enter) Router(config-line)#password Router(config-line)#password xxxx Router(config-line)#login Router(config-line)#login
To set username & password for the user mode Router(config)#username Router(config)#username xxxx password xxxx Router(config)#Line Router(config)#Line console 0 -2-
Router(config-line)#login Router(config-line)#login local
To change the hostname Router(config)#hostname Router(config)#hostname HOR(enter) HOR(enter) HOR(config)#
T o encrypt all the passwords Router(config)#service Router(config)#service password-encryption password-encryption
To set password for the privileged mode Router(config)#enable Router(config)#enable password/secret xxxx
QUESTIONS 1 . What are are the different modes modes in a router? router? o
o
Router> ------------- User mode or the user executable mode Enable (enter) Router# ---------- Privileged mode/Enable mode Show running-config Debug xxx -3-
Ping A.B.C.D o
o o
Router# configure terminal (enter) Router(config)# ----------- Global configuration mode Router(config)#interface Router(config)#interface ethernet 0/fastethernet 0/serial 0/ serial 1(enter) Router(config)# line console 0 Router(config-if/line)# ---------- Specific configuration mode
2 . Difference between between Login and Login Login Local? o
o
Login activates the usermode entry password for a single user without username. Login local activates the username and password for the same usermode, incase of multiple users.
3 . How to encrypt our passwords? o
Router(config)#service Router(config)#service password-encryption password-encryption – Encrypts all the passwords at a time. The passwords once encrypted, cannot be decrypted by any command.
4 . How to set password password to the user mode? mode? o
Router(config)#Line Router(config)#Line console 0(enter) Router(config-line)#password Router(config-line)#password xxxx Router(config-line)#login Router(config-line)#login - Login activates the usermode entry password for a single user without username.
5 . How to set password password to the privilege mode? mode? o
Router(config)#enable Router(config)#enable password/secret password/secret xxxx
6 . How to set username and password password to the user mode? mode? o o
Router(config)#username Router(config)#username xxxx password xxxx Router(config-line)#login Router(config-line)#logi n local - Login local activates the username and password for the same usermode, incase of multiple users.
STATIC ROUTING DTE 10.0.0.1
DCE 20.0.0.1
20.0.0.2
30.0.0.1 10n/w 30 n/w E0
S0
S0 -4-
E0
HOR
BOR
R1(config)#interface e 0 R1(config-if)#ip address 10.0.0.1 255.0.0.0 R1(config-if)#no shutdown *
R2(config)#interface e 0 R2(config-if)#ip address 30.0.0.1 255.0.0.0 R2(config-if)#no shutdown
R1(config)#interface s 0 R2(config)#interface s 0 R1(config-if)#ip address 20.0.0.1 255.0.0.0 R2(config-if)#ip address 20.0.0.2 255.0.0.0 R1(config-if)#no shutdown R2(config-if)#clock rate 64000 R2(config-if)#no shutdown R1(config)#ip route 30.0.0.0 255.0.0.0 20.0.0.2 ** R2(config)#ip route 10.0.0.0 255.0.0.0 20.0.0.1 ** * All interfaces are administratively down when the router is switched on. We change their status to up by using the command ‘no shutdown’. ** In static routing, we are manually adding the destination network to our Routing table. Router(config-if)# ip route
Next hop address refers to the address of the next router that receives the packet and then forwards it to the remote location.
Commands 1 . Router#show running-config This will display the current configuration of the router.
-5-
2 . Router#show controllers serial 0 To identify the DCE & DTE ends of the Serial cable. 3 . Router#show interface ethernet 0 This will displays the details of ethernet interface. 4 . Router#show interface serial 0 This will display the details of serial interface. 5. Router#show ip interface brief This will display the interface & line protocol status in a tabular format.
Outputs Router#sh running-config interface Ethernet0 ip address 10.0.0.1 255.0.0.0 ! interface Ethernet1 no ip address shutdown ! interface Serial0 ip address 20.0.0.2 255.0.0.0 clockrate 64000 ! interface Serial1 no ip address shutdown ! IP route 30.0.0.0 255.0.0.0 20.0.0.1 ! line con 0 line aux 0 line vty 0 4 login ! End
Router#sh int e0 Ethernet0 is up, line protocol is up Hardware is Lance, address is 0010.7b80.c3c6 (bia 0010.7b80.c3c6) Internet address is 10.0.0.1/8 -6-
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set, keepalive set (10 sec)
Router#sh int s0 Serial0 is up, line protocol is up Hardware is HD64570 Internet address is 20.0.0.2/8 MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation HDLC, loopback not set, keep alive set (10 sec)
Router#show ip int brief State 1 - When both no shutdown and clock rate is applied to corresponding interfaces Interface
IP-Address
OK? Method Status
Ethernet0 Serial0
30.0.0.1 20.0.0.2
YES YES
manual manual
Protocol
up up
up up
Router#show ip int brief State 2 - When clock rate is not given on DCE end & layer 1 problem Interface
IP-Address
OK? Method
Status
Protocol
Ethernet0 Serial0
30.0.0.1 20.0.0.2
YES manual YES manual
up up
up down
Router#show ip int brief State 3 - When the other end serial interface is shut down Interface
IP-Address
OK? Method
Status
Protocol
Ethernet0 Serial0
30.0.0.1 20.0.0.2
YES YES
up down
up down
manual manual
Router#show controllers s 0 HD unit 0, idb = 0xB883C, driver structure at 0xBDB98 buffer size 1524 HD unit 0, V.35 DCE cable, clockrate 64000
-7-
Router#show ip route Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default Gateway of last resort is not set C 20.0.0.0/8 is directly connected, Serial0 C 10.0.0.0/8 is directly connected, Ethernet0 S 30.0.0.0/8 [1/0] via 20.0.0.1 Router#sh protocols Global values: Internet Protocol routing is enabled Ethernet0 is up, line protocol is up Internet address is 10.0.0.1/8 Ethernet1 is administratively down, line protocol is down Serial0 is up, line protocol is up Internet address is 20.0.0.2/8 Serial1 is administratively down, line protocol is down
Questions 1 . How to assign an IP address to the Router and configure it? o
Router(config)interface e 0 / s 0 -8-
Router(config-if)ip address Router(config-if)no shutdown We assign our default-gateway as the IP address to the ethernet port. When the router is switched ON, by default all the interfaces are administratively
down. To make the interfaces up we give no shutdown 2 . Why and where we use the clock rate? o
The serial line has two ends DTE and DCE. This line goes up and down when IP address and no shutdown is configured on both sides and will be in asynchronous state always. To synchronize the link clock rate should be configured at DCE end.
3 . How to find out the DCE end? o
Router#sh controllers s 0
4 . Difference between Request timed out Destination host unreachable Reply from : timeget frame.txt 200 PORT command successful. 226 Transfer complete. ftp:28 bytes received in 0.00seconds 26000.00kbytes/sec. ftp>bye
Questions - 17 -
1. Difference between Static Routing & Dynamic Routing? o
In static routing, we are manually adding the destination network to our Routing table.
o
In Dynamic Routing, the protocols build the routing table automatically.
2. Difference between RIP and IGRP?
Interior Gateway Routing Protocol
Routing Information Protocol
Uses autonomous number system.
Does not use autonomous number system.
Works only on Cisco routers.
Works on multi-vendor routers.
Sends updates for every 90secs.
Sends updates for every 30secs.
Bandwidth, delay and distance as a unit of metric.
Hop count as a unit of metric.
Administrative distance is 100
Administrative distance is 120
Has a maximum hop count of 100
Has a maximum hop count of 16
Time Intervals
RIP
IGRP
Update Interval
30
90
Hold-down timer
180
280
Invalid after
180
270
Flushed after
240
630
. 3 . What is Routing loop and when it occurs? - 18 -
Distance-vector routing protocols sends routing table updates at regular intervals to keep track of any changes in the Internetwork. Routing loops can occur when a network outage happens and no router is updated with the change in routing table. Ra
Rb
Rc n/w 3
Re n/w 4
n/w 5
Rd o
o
o
o
o
Assume that the first update has been received by every router and now they are in the due of 29sec. Now, the interface to Network 5 is down and also all routers know about Network 5. Then Re prompts Rc to stop routing to Network 5 through it. But Ra, Rb and Rd don’t know about Network 5 yet, so they keep sending the updates. Rc will be sending its update and cause Rb to stop routing to Network 5, but Ra and Rd are not updated. To them, it appears that Network 5 is still available through Rb. Ra will continue to send its updates for every 30secs and unfortunately Rb and Rd receives a message that Network 5 can be reached from Ra. So Rb and Rd sends the information that Network 5 is available. Any packet destined for Network 5 will go from Ra to Rb and then back to Ra. This leads to a routing loop.
3. Methods to avoid Routing loop? Maximum hop count: When the routing loop occurs, the hop count increases indefinitely each time a packet passes through a router. To resolve this maximum hop count was defined. RIP permits hop count up to 15, so anything that requires 16th hop will be considered as unreachable. Split horizon: Split horizon defines that the routing information cannot be sent back in the direction from which it was received i.e., the routing protocol determines which interface a network route was learned on and it won’t advertise the route back to that same interface.
Route poisoning: - 19 -
This helps to avoid routing loops in a meshed structure even if split horizon works out. E.g. when Network 5 goes down, Re initiates route poisoning by advertising Network 5 as 16 hops or unreachable, this poisoning of the route to Network 5 keeps Rc from being susceptible to incorrect updates about the route to Network 5. When Rc receives a route poisoning from Re; it sends an update, called
“Poison
reverse” back to Re. This ensures all routes on the segment have
received the poisoned route information. 4. Define Hold down timer o
This sets the amount of time for which the routing information is suppressed. Routes will enter into the hold down state, when an update packet is received indicating the route as unreachable. This continues, either till it receives an update packet with a better metric or till the hold down timer is expired. By default Hold down timer is for 180 seconds.
5. You type “debug ip rip ” on your router console and see that 172.16.10.0 is being advertised to you with a metric of 16. What does this mean? o
The route is inaccessible.
6. What command is used to stop RIP routing updates from exiting out an interface but still receive RIP route updates? o
Router(config-router)#passive-interface s0
7. A network that is advertised by both RIP and IGRP appears in the routing table flagged as an IGRP route. Why is the RIP route to this network not used in the routing table? o
IGRP has a lower administrative distance
8. Which parameters does IGRP use to find out the best path to a remote network? o
Bandwidth and Delay.
9. Which command displays RIP routing updates? o
Router#debug ip rip
TELNET
- 20 -
10.0.0.1
20.0.0.1
10 n/w
20.0.0.2
30.0.0.1
20 n/w
30
n/w
Make sure you are able to ping the destination network before you configure WAN Protocols
R1(config)#line vty 0 4 R1(config-line)#password xxx R1(config-line)#Login R1(config)#enable password xxx
R2(config)#line vty 0 4 R2(config-line)#password xxx R2(config-line)#Login R2(config)#enable password xxx
If vty password is not configured in R2 R1#telnet 20.0.0.2 Password required, but none set Connection to 20.0.0.2 is closed
After password is configured on R2, try to telnet R2(20.0.0.2) R1>telnet 20.0.0.2 User access verification Password:
If password is not enabled for the privileged mode R2>enable %No password set
If the password is set R2>enable Password: R2#
R2>exit R1#
----------- Will disconnect the session.
R2>(Press) ctrl + shift + 6 and x R1# ----------- Will suspend the session.
Commands
- 21 -
1. R1#sh sessions - To display the sessions opened by a particular user. 2. R1#(enter)(enter) - To move to the lastly opened session 3. R1#sh users - To display the users logged on 4. R1#clear line 3 - To disconnect a user [Confirm] R1# 5. R1#sh cdp Works only on directly connected Cisco routers CDP runs every 60 sec. 6. Hold time – 180 sec. 7. R1#sh cdp neighbors R1#sh cdp neighbors Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge S - Switch, H - Host, I - IGMP, r - Repeater Device ID Router
Local Intrfce Ser 0
Holdtme Capability Platform Port ID 143 R 2500 Ser 0
8. R1#show cdp neighbors detail ------------------------Device ID: Router Entry address(es): IP address: 20.0.0.2 Platform: cisco 2500, Capabilities: Router Interface: Serial0, Port ID (outgoing port): Serial0 Holdtime : 122 sec Version : Cisco Internetwork Operating System Software IOS (tm) 2500 Software (C2500-IS-L), Version 12.3(13), RELEASE SOFTWARE (fc2) Technical Support: http://www.cisco.com/techsupport Copyright (c) 1986-2005 by cisco Systems, Inc. Compiled Thu 10-Feb-05 11:49 by ssearch advertisement version: 2
9. R1(config)#ip host 20.0.0.2 – Creates Host Table.
Outputs Router#sh sessions - 22 -
Conn Host 1 20.0.0.1 * 2 20.0.0.1
Address 20.0.0.1 20.0.0.1
Byte Idle Conn Name 0 0 20.0.0.1 0 0
Router#sh users Line * 0 con 2 vty
User 0 0
Host(s) 20.0.0.1 20.0.0.1 idle
Idle 00:06:03 00:05:42 00:07:45
Location
20.0.0.1
Security Device Manager (SDM) – GUI
- 23 -
Security Device Manager (SDM) is a web-based device-management tool for Cisco routers that can simplify router deployments by allowing us to manage and troubleshoot complex network and connectivity issues and also supports a wide range of Cisco IOS Software releases to set up advanced configurations. It is used to configure a router through a HTTP service. To do this make sure your router is configured with atleast one ip address on a LAN interface and connects a host to the router. Would you like to enter the initial configuration dialog? [yes/no]: n Press RETURN to get started! Router>en Router#config t Enter configuration commands, one per line. End with CNTL/Z. Router(config)#int f0/0 Router(config-if)#ip address 1.1.1.1 255.255.255.0 Router(config-if)#no shut Router(config-if)#do ping 1.1.1.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 1.1.1.2, timeout is 2 seconds: !!!!! From here, you just open a browser & type http://1.1.1.1, SDM gets loaded and open a window.
Clicking the Configure button at the top of the page, choose the type of interface we want to configure and then click the Create New Connection button at the bottom of the page (fig.1a). This opens the LAN or WAN wizard, depending on which interface we chose to configure. By clicking the Edit Interface/Connection tab, you get to see your interface status. (fig.1b).
- 24 -
Fig.1a
Fig.1b You can double-click to edit that particular interface. Click on the Additional Tasks Button at the bottom left portion and then select Router properties icon. Here, you can set the hostname, MOTD banner, and enable secret password.
You can also create a DHCP pool on your router. Click on the DHCP folder, then the DHCP pool icon and then click Add button.
Questions
- 25 -
1. Difference between exit and using ctrl+shift+6 x? Using exit command will disconnect the current session Using ctrl+shift +6 x command we can suspend a session without disconnecting that session
2. Differentiate between show sessions and show users?
Show sessions will show the sessions we opened by telnet ting to the corresponding Destinations. Show users will show the sessions opened by other destinations to us.
3. What are two characteristics of Telnet? (Choose two.)
It sends data in clear text format. It is no longer supported on Cisco network devices. It is more secure than SSH. It requires an enterprise license in order to be i mplemented. It requires that destination device be configured to support Telnet connections.
A and E th
4. What happens if we try to open a 6 session to a destination?
th
If 6 session is opened an error message is displayed. R1#telnet Trying Telnet < destination IP address > % connection refused by remote host.
5. What are two reasons a network administrator would use CDP? (Choose two.) to verify the type of cable interconnecting two devices to determine the status of network services on a remote device to obtain VLAN information from directly connected switches to verify Layer 2 connectivity between two devices when Layer 3 fails to obtain the IP address of a connected device in order to telnet to the device to determine the status of the routing protocols between directly connected routers
D and E
ACCESS CONTROL LISTS (ACL) - 26 -
In
Out R
R E0
S0
Out
S0
E0
In
LAN1 LAN2 30.0.0.0 10.0.0.0
An access list is a list of conditions that classify the packets (or) the packet definition). Unauthorized access can be blocked by using access list. These lists can be used to control the traffic passing through the router. Following are different types of access lists. Standard ACL - Access-list No.1-99
Action, ACL number, Source IP, SWCM (Source Wild Card Mask) are the parameters to be considered while configuring standard ACL which considers only the source address when rules are defined and to be checked. Syntax: R1(config)#Access-list R1(config)#Access-list 5 deny 30.0.0.10 0.0.0.0 R1(config)#Access-list 5 permit 30.0.0.15 0.0.0.0 - Here it considers the source address only Once you have defined the access-list, binding should be done at the interface
required (E0 or S0). For an interface at any time there are maximum of two binding (in and out).
R1(config)#int e 0 / s0 R1(config-if)#ip Access-group 5 in/out For binding we consider two directions: In & Out. This specifies the direction in which the
data packets are moving with respect to the Router.
Extended ACL - Access-list No. 100-199
Action, ACL number, Source IP, SWCM (Source Wild Card Mask), Destination IP, DWCM, Protocol, interface and the destination port number are the parameters considered while configuring Extended ACL.
- 27 -
Syntax: R1(config)#Access-listeq Port no - can be replaced by the port names. Source IP – From IP address. Destination IP – To IP address. Eq – equivalent to. Action – permit or deny.
R1(config)#Access-list 101 deny TCP 10.0.0.10 0.0.0.0 30.0.0.10 0.0.0.0 eq 80 R1(config)#Access-list 101 permit TCP 10.0.0.10 0.0.0.0 30.0.0.10 0.0.0.0 eq 23 R1(config)#Access-list 101 deny ICMP any any Syntax: R1(config)#Access-listeq log R1(config)#Access-list 101 deny TCP 10.0.0.10 0.0.0.0 30.0.0.10 0.0.0.0 eq ftp log Log - gives information about the port no of source, number of packets send, number of
matches made etc.,
NAMED ACCESS LIST Standard
R1(config)#IP Access-list standard R1(config)#IP access-list standard moon R1(config-std-nacl)# R1(config-std-nacl)#deny 30.0.0.10 0.0.0.0 R1(config-std-nacl)# permit 30.0.0.15 0.0.0.0 Extended
R1(config)#IP Access-list Extended R1(config)#ip access-list extended sun R1(config-ext-nacl)#eq R1(config-ext-nacl)#deny TCP 10.0.0.10 0.0.0.0 30.0.0.10 0.0.0.0 eq www R1(config-ext-nacl)#permit TCP 10.0.0.10 0.0.0.0 30.0.0.10 0.0.0.0 eq telnet R1(config-ext-nacl)#deny ICMP any any
- 28 -
Command 1 . Show access-lists This displays all the access lists created.
Output Router#sh access-lists Extended access-list 123 10 deny tcp host 10.0.0.10 host 30.0.0.10 eq telnet
Questions 1 . Different types of Access lists? o
o
o
Standard Access Lists - Standard access list considers only the source address. Deny/Permit actions are applied on the source address. Once the access list is defined, binding can be done at any one of the interface (Ethernet or serial). Extended Access Lists - This considers source address, Destination address, protocol, destination ports etc .In Extended access list we can specify the applications that are to be permitted or denied from the source to destination. Named Access Lists - As the name suggests, we can define an access list using a name instead of number wherein we can modify (or delete) the list by individual conditions which is not possible in the numbered lists.
2 . Difference between numbered access lists and named access lists? o
In numbered access lists, if we try to delete an individual statement from the access list, the whole list will be deleted. In named access lists, we can edit the list by individual statement.
3 . what are the benefits provided by access control lists (ACLs)? o o o
ACL helps to define the packet parameters ACLs classify and organize network traffic ACLs provide IP route filtering
4 . Which command is required to apply an access list on a virtual terminal line of a router? o
Router(config-line)# access-class 10 in
5 . Which single access list statement will combine all four of these statements into a - 29 -
single statements that will have exactly the same effect? access-list 15 permit 172.29.16.0 0.0.0.255 access-list 15 permit 172.29.17.0 0.0.0.255 access-list 15 permit 172.29.18.0 0.0.0.255 access-list 15 permit 172.29.19.0 0.0.0.255 o
access-list 10 permit 172.29.16.0 0.0.3.255
6 . If you want to deny all Telnet connections to the network 192.168.10.0, which Command will you use? o
access-list 100 deny tcp any 192.168.10.0 0.0.0.255 eq 23
7 . What are the possible ways to refer to a host 172.16.30.55 in an IP access list? o o
172.16.30.55 0.0.0.0 host 172.16.30.55
8 . Which access lists will allow only HTTP traffic into network 196.15.7.0? o
access-list 100 permit tcp any 196.15.7.0 0.0.0.255 eq www
9. Which command connect access list 110 inbound to interface ethernet0? o o
Router(config)#interface ethernet 0 Router(config-if)#ip access-group 110 in
- 30 -
NETWORK ADDRESS TRANSLATION (NAT)
20.0.0.2 R
Private 10.0.0.10
Public 30.0.0.20 Inside local
Inside global
R1(config)#Ip route 0.0.0.0 0.0.0.0 S0 -------------- Default Network R1(config)#access-list 15 permit 10.0.0.0 0.255.255.255 -------- Defining the range of hosts R1(config)#int e 0 R1(config-if)#ip NAT inside R1(config)#int s 0 R1(config-if)#ip NAT outside
1.
Dynamic NAT configuring R1(config)#IP NAT inside source list 15 int S0 overload *
2.
Pool NAT R1(config)#IP NAT pool MOHAN 20.0.0.30 20.0.0.35 netmask 255.0.0.0 R1(config)#IP NAT inside source list 15 pool MOHAN overload **
3.
Static NAT R1(config)#IP NAT inside source static 10.0.0.10 20.0.0.5 ***
* Router translates source addresses reaching inside (say e0) if it matches the list, to the same public address at serial interface. ** Router translates source addresses reaching inside (say e0) if it matches the list, from the range of addresses mentioned in the pool. *** When a packet comes from 10.0.0.10 through inside source, then source is always translated to only one address (20.0.0.5) and vice versa.
- 31 -
Commands
1. Router#debug ip nat
------------- To debug NAT
2. Router#sh ip nat translations ----------- To display translations( Displays Inside local, Inside Global, Outside local and Outside Global ) 3. R1#clear ip nat translations * -----------
To clear translations
OUTPUTS Router#debug ip nat IP NAT debugging is on Router# 01:10:59: NAT*: s=10.0.0.10->20.0.0.5, d=30.0.0.1 [205] 01:10:59: NAT*: s=30.0.0.1, d=20.0.0.5->10.0.0.10 [205] 01:11:00: NAT*: s=10.0.0.10->20.0.0.5, d=30.0.0.1 [206] 01:11:00: NAT*: s=30.0.0.1, d=20.0.0.5->10.0.0.10 [206] Router#sh ip nat translations Pro ICMP
Inside global Inside local 20.0.0.5 10.0.0.10
- 32 -
Outside local ---
Outside global ---
Questions 1. What is NAT?
Network Address Translation involves re-writing the source and destination address of packets as they pass through a router. NAT is done in order to enable multiple hosts on a private network to access the Internet using a single public IP address.
2. What does the Inside Global address represent in the configuration of NAT?
A registered address that represents an inside host to an outside network
3. Why we use access-list in NAT?
Access-list defines the range of the hosts that can access the global address.
4. A network technician at Mohans would like to implement NAT in the network shown in the exhibit. Inside hosts are allowed to use a private addressing scheme. Where NAT should be configured?
R3
R2
R1
Internet
Pc1
Pc2 Pc3
Pc4
Router R3
5 . Type of NAT that utilizes different ports to map multiple IP addresses to a single globally registered IP address?
Overloading
6. What is the function of the Cisco IOS command ip nat inside source static 10.1.1.5 172.35.16.5? It creates a global address pool for all outside NAT transactions. It establishes a dynamic address pool for an inside static address. It creates dynamic source translations for all inside local PAT transactions. It creates a one-to-one mapping between an inside local address and an inside global address.
D
- 33 -
7. What flavor of Network Address Translation can be used to have one IP address allow many users to connect to the global Internet? NAT Static Dynamic PAT Overloading
E
8. Which of the following are disadvantages of using NAT? (Choose three.) Translation introduces switching path delays. Conserves legally registered addresses.
Causes loss of end-to-end IP traceability. Increases flexibility when connecting to the Internet. Certain applications will not function with NAT enabled. Reduces address overlap occurrence.
A,C and E
- 34 -
OSPF & EIGRP
10.0.0.0 30.0.0.0
10.0.0.1 R
20.0.0.1
20.0.0.2 R2
30.0.0.1
OSPF Router(config)#router OSPF ------- [Process-id 1 to 65535] Router(config-router)#network area
R1(config)#router OSPF 15 R1(config-router)#network 10.0.0.0 0.255.255.255 area 0 R1(config-router)#network 20.0.0.0 0.255.255.255 area 0 R2(config)#router OSPF 12 R2(config-router)#network 30.0.0.0 0.255.255.255 area 0 R2(config-router)#network 20.0.0.0 0.255.255.255 area 0 Between two OSPF routers the process-ids need not be the same
EIGRP R1(config)#router EIGRP ---------- [autonomous-no 1 to 65535] R1(config-router)#network R1(config)#router EIGRP 123 R1(config-router)#network 10.0.0.0 R1(config-router)#network 20.0.0.0 R2(config)#router EIGRP 123 R2(config-router)#network 30.0.0.0 R2(config-router)#network 20.0.0.0 The autonomous system numbers should be the same while communicating
EIGRPs In OSPF, area should be same.
- 35 -
between
Loop back interface It’s a logical interface i.e., not a real router interface. When the Router ID of a routerinterface with the highest address, goes up and down, re-election for the new DR will not get completed. Loop back interface resolves this problem, as it never goes down & router id never changes.
Types of network using OSPF
Broadcast (multi-access) networks provide a broadcast ability in which every single broadcast is delivered to all nodes on the network. This can be avoided in OSPF by electing a DR and BDR for each broadcast multi-access networks.
LSA
LSA
LSA
Non-broadcast multi-access network allows for multi-access, but have no broadcast ability. So, NBMA networks require special OSPF configuration to function properly and neighbor relationships must be defined.
Here, Information of Ra is not sent to Rc Information of Rc is not sent to Ra But Rb knows about Ra and Rc
Point-to-point refers to a type of network topology consisting of a direct connection between two routers that provides a single communication path. This type of configuration eliminates the need for DRs or BDRs, but neighbors are discovered automatically.
R
R
- 36 -
Commands OSPF
Router#sh ip ospf interface e 0 Router#sh ip ospf int f 0 Router#sh ip ospf int s 0 Router#sh ip ospf neighbor shows neighbor router-id. Router#sh ip protocols
EIGRP
Router#sh ip eigrp neighbors Router#sh ip eigrp topology Router#sh ip eigrp traffic
- 37 -
OUTPUTS
Router#debug ip ospf events OSPF events debugging is on Router# OSPF: Rcv hello from 100.0.0.1 area 0 from Serial0 20.0.0.2 OSPF: End of hello processing OSPF: Rcv hello from 100.0.0.1 area 0 from Serial0 20.0.0.2 OSPF: End of hello processing OSPF: Rcv hello from 100.0.0.1 area 0 from Serial0 20.0.0.2 OSPF: End of hello processing
Router#sh ip ospf int e0 Ethernet0 is up, line protocol is up Internet Address 30.0.0.1/8, Area 0 Process ID 5, Router ID 30.0.0.1, Network Type BROADCAST, Cost: 10 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 30.0.0.1, Interface address 30.0.0.1 No backup designated router on this network Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Neighbor Count is 0, Adjacent neighbor count is 0 Suppress hello for 0 neighbor(s)
Router#sh ip ospf int s0 Serial0 is up, line protocol is up Internet Address 20.0.0.1/8, Area 0 Process ID 5, Router ID 30.0.0.1, Network Type POINT_TO_POINT, Cost: 64 Transmit Delay is 1 sec, State POINT_TO_POINT, Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 100.0.0.1 Suppress hello for 0 neighbor(s)
Router#sh ip eigrp topology IP-EIGRP Topology Table for process 5 Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply, r - Reply status P 20.0.0.0/8, 1 successors, FD is 2169856 via Connected, Serial0 P 30.0.0.0/8, 1 successors, FD is 281600 via Connected, Ethernet0 P 100.0.0.0/8, 1 successors, FD is 2195456 via 20.0.0.2 (2195456/281600), Serial0
- 38 -
Questions
1. Differentiate between Distance vector and Link state Protocol?
Sl. No
Distance vector
Link state
1
Considers only distance.
Bandwidth, delay, load, Reliability and MTU.
2
Sends the routing table.
Sends the state of the link.
3
Learns about the adjacent routers.
Learns the entire topology.
2. Differentiate between OSPF and EIGRP? Sl. No 1 2
OSPF Link state.
EIGRP Hybrid(DV + LS).
Open protocol (multi-vendor).
Cisco Proprietary Protocol.
Supports only IP protocol.
Supports multiple protocols like IP, IPX, Apple Talk etc.,
3 4
Cost = 10 / Bandwidth.
Cost is calculated based on the Bandwidth, Delay etc.,
5
Link State Advertisement (LSA) is made. (State of Link is broadcasted).
Routing Table is sent.
6
For every 10 sec a Hello packet is sent.
For every 5 sec a Hello packet is sent.
7
For every 30 min LSA is broadcasted.
Broadcast is sent only when there is a change in the Routing table.
8
When the Link goes down OSPF needs to run the SPF algorithm again.
9
Area is used for administrative convenience of a large network
When the link goes down EIGRP proceeds with the Next Best Path (Feasible Successor). Autonomous System is used for administrative convenience of a large network
10
Uses Dijsktra algorithm to find the best path (Shortest path).
- 39 -
Uses DUAL (Diffusing Update Algorithm) is used to find the best path.
Backbone Router Switch 3. How OSPF works out? ABR
Area 1
Area 1
ABR
Area 0 ABR
Area 2
Area 3
ASBR
Internal Router
AS 100
AS 200
Area 1 ABR – Area Border Router. ASBR – Autonomous System Border Router. AS – Autonomous System.
OSPF is designed to have a hierarchical structure as large networks are a bit difficult to manage. This allows to decrease routing overhead and to confine n/w instability to single area of n/w.
OSPF must have an area 0 (backbone area) and all routers should connect to this area. But routers (i.e., ABRs) that connect other areas to backbone area should have at least one interface connecting to area 0.
4. Show commands that will display the state of the OSPF DR/BDR election process?
Router# show ip ospf interface - 40 -
5. Which command will display all the EIGRP feasible successor routes known to a router?
Router# show ip eigrp topology
6. When designing OSPF networks; what is the purpose of using a hierarchical design?
To speed up convergence To confine network instability to single areas of the network To reduce routing overhead
7. If routers in a single area are configured with the same priority value, what value router use for the OSPF Router ID?
does a
The highest IP address of any physical interface
8. Which one of the following EIGRP commands can check the IP addresses of the adjacent neighbors?
R1#show ip eigrp neighbors
9 . Which commands will place network 10.2.3.0/24 into area 0?
Router(config)# router ospf 10 Router (config_router) # network 10.2.3.0 0.0.0.255 area 0
10. With which network type will OSPF establish router adjacencies but not perform DR/BDR election process?
Point-to-point
11. Which is true regarding EIGRP successor routes?
A successor route may be backed up by a feasible successor route. A successor route is used by EIGRP to forward traffic to a destination. o
A
12. A network administrator typed the following into his router:
- 41 -
the
Router(config)# router ospf 1 Router(config-router)#network 10.0.0.0 255.0.0.0 area 0 But still he can’t see any routes in the routing table. What configuration error did administrator make?
The wildcard mask is incorrect. The wildcard should have been 0.255.255.255.
13 . Which EIGRP information is held in RAM and maintained through the use of Hello and update packets?
Neighbor table Topology table o
A
ROUTING INFORMATION PROTOCOL VERSION 2
- 42 -
the
10.0.0.1 10.0.0.0
20.0.0.1
20.0.0.2
R
E0
30.0.0.1
R
S0
R1(config)#router RIP R1(config-router)#version 2 R1(config-router)#network 10.0.0.0 R1(config-router)#network 20.0.0.0
30.0.0.0 S0
E0
R2(config)#router RIP R2(config-router)#version 2 R2(config-router)#network 20.0.0.0 R2(config-router)#network 30.0.0.0
Here the command ‘version 2’ is added to the RIP protocol to change it to RIPv2. Authenticating Packets using RIPv2
R1(config)#Key chain ABC R1(config-keychain)#key 2 R1(config-keychain-key)#key-string 123
// Key chain // Key Identifier // Key-string Line
R2(config)#Key chain XYZ R2(config-keychain)#key 2 R2(config-keychain-key)#key-string 123 The Key identifier and the Key-string should be same on the both end routers. R1(config)#int s0 R1(config-if)#ip rip authentication key-chain ABC R1(config-if)#ip rip authentication mode text / md5 R2(config)#int s0 R2(config-if)#ip rip authentication key-chain XYZ R2(config-if)#ip rip authentication mode text / md5 Text and md5 are the two authentication methods used in RIPv2. By default RIPv2 can send & receive only version 2 updates. RIPv2 also allows sending and receiving version 1 updates on any of the interface. R1(config)#int s0 R1(config-if)#ip rip send / receive version 1 2 R2(config)#int s0 R2(config-if)#ip rip send / receive version 1 2
RIP version 2 has all its characteristics same as RIPv1 except some changes. - 43 -
Difference between Routing Protocols: RIPv1
IGRP
OSPF
EIGRP
RIPv2
Protocol
Distance vector
Distance vector
Link state
Hybrid ( DV + LS )
Distance vector
Multi vendor support
Yes
No
Yes
No
yes
Metric
Hop count
Bandwidth & Delay
Cost
Bandwidth & Delay
Hop count
Sends
Routing table updates
Routing table updates
Link state advertiseme nt
Routing table updates
Routing table updates
Routing table Update intervals
30 sec
90 sec
30 min
Whenever a change occurs
30 sec
Supports VLSM
No
No
Yes
Yes
Yes
Supports
Classful
Classful
Classless
Classless
Classless
Uses
255.255.255.2 55
255.255.255.255
224.0.0.5 224.0.0.6
224.0.0.10
224.0.0.9
Outputs
- 44 -
After RIPv2 is configured on both the routers Router#debug ip rip RIP protocol debugging is on Router# RIP: sending v2 update to 224.0.0.9 via Ethernet0/0 (10.0.0.1) RIP: build update entries 20.0.0.0/8 via 0.0.0.0, metric 1, tag 0 30.0.0.0/8 via 0.0.0.0, metric 2, tag 0 RIP: sending v2 update to 224.0.0.9 via Serial0/1 (20.0.0.1) RIP: build update entries 10.0.0.0/8 via 0.0.0.0, metric 1, tag 0 RIP: received v2 update from 20.0.0.2 on Serial0/1 30.0.0.0/8 via 0.0.0.0 in 1 hops
RIPv2 on one router & the other end is configured with RIPv1 Router#debug ip rip RIP protocol debugging is on Router# RIP: sending v2 update to 224.0.0.9 via Serial0 (20.0.0.2) RIP: build update entries 30.0.0.0/8 via 0.0.0.0, metric 1, tag 0 RIP: sending v2 update to 224.0.0.9 via Ethernet0 (30.0.0.1) RIP: build update entries 10.0.0.0/8 via 0.0.0.0, metric 2, tag 0 20.0.0.0/8 via 0.0.0.0, metric 1, tag 0 RIP: ignored v1 packet from 20.0.0.1 (illegal version)
Using debug command on the other end. Router#debug ip rip RIP protocol debugging is on Router# RIP: sending v1 update to 255.255.255.255 via Ethernet0/0(30.0.0.1) RIP: build update entries network 10.0.0.0 metric 2 network 20.0.0.0 metric 1 RIP: sending v1 update to 255.255.255.255 via Serial0/1 (20.0.0.2) RIP: build update entries network 30.0.0.0 metric 1 RIP: received v2 update from 20.0.0.1 on Serial0/1 10.0.0.0/8 via 0.0.0.0 in 1 hops
Router#show ip protocols Routing Protocol is "rip" - 45 -
Sending updates every 30 seconds, next due in 21 seconds Invalid after 180 seconds, hold down 180, flushed after 240 Redistributing: rip Default version control: send version 2, receive version 2 Interface Send Recv Triggered RIP Key-chain Ethernet0/0 2 2 Serial0/1 2 2 Routing for Networks: 20.0.0.0 30.0.0.0 Routing Information Sources: Gateway Distance Last Update 20.0.0.1 120 00:00:03 Distance: (default is 120) [ By default RIPv2 can send & receive only version 2 updates ]
Authentication modes is text on both routers Router#debug ip rip RIP protocol debugging is on Router# RIP: sending v2 update to 224.0.0.9 via Ethernet0 (30.0.0.1) RIP: build update entries 10.0.0.0/8 via 0.0.0.0, metric 2, tag 0 20.0.0.0/8 via 0.0.0.0, metric 1, tag 0 RIP: received packet with text authentication abc RIP: received v2 update from 20.0.0.1 on Serial0 10.0.0.0/8 via 0.0.0.0 in 1 hops RIP: sending v2 update to 224.0.0.9 via Serial0 (20.0.0.2) RIP: build update entries 30.0.0.0/8 via 0.0.0.0, metric 1, tag 0
md5 is the authentication mode on both routers Router#debug ip rip RIP protocol debugging is on Router# RIP: sending v2 update to 224.0.0.9 via Serial0 (20.0.0.2) RIP: build update entries 30.0.0.0/8 via 0.0.0.0, metric 1, tag 0 RIP: sending v2 update to 224.0.0.9 via Ethernet0 (30.0.0.1) RIP: build update entries 10.0.0.0/8 via 0.0.0.0, metric 2, tag 0 20.0.0.0/8 via 0.0.0.0, metric 1, tag 0
RIP: received packet with MD5 authentication RIP: received v2 update from 20.0.0.1 on Serial0 - 46 -
10.0.0.0/8 via 0.0.0.0 in 1 hops
Different Authentication modes on both ends i.e., md5 authentication on one end & text on the other end. Router#debug ip rip RIP protocol debugging is on Router# RIP: ignored v2 packet from 20.0.0.1 (invalid authentication) RIP: sending v2 update to 224.0.0.9 via Ethernet0 (30.0.0.1) RIP: build update entries 20.0.0.0/8 via 0.0.0.0, metric 1, tag 0 RIP: sending v2 update to 224.0.0.9 via Serial0 (20.0.0.2) RIP: build update entries 30.0.0.0/8 via 0.0.0.0, metric 1, tag 0
Questions 1. Which three statements are correct about RIPv2? - 47 -
It has the same maximum hop count as version 1 It uses broadcasts for its routing updates It is a classless routing Protocol It has a lower administrative distance than RIPv1 It supports authentication o
It has the same maximum hop count as version 1
o
It is a classless routing Protocol
o
It supports authentication
2. Which statement is true regarding classless routing protocols? (Choose two.)
The use of discontinuous networks is not allowed. The use of variable length subnet masks is permitted. RIPv1 is a classless routing protocol. IGRP supports classless routing within the same autonomous system. RIPv2 supports classless routing. o
The use of variable length subnet masks is permitted
o
RIPv2 supports classless routing.
3. RIPv2 uses ---- to send the routing table updates
Broadcast Multicast Unicast o
Multicast
4. The network shown in the exhibit is running the RIPv2 routing protocol. The fastEthernet0/0 interface on R1 goes down. In which two ways will the routers in this network respond to this change? (Choose two.)
A. All routers will reference their topology database to determine if any backup routes to the 192.168.1.0 network are known.
- 48 -
B. Routers R2 and R3 mark the route as inaccessible and will not accept any further routing updates from R1 until their hold down timers expire. C. Because of the split-horizon rule, router R2 will be prevented from sending erroneous information to R1 about connectivity to the 192.168.1.0 network. D. When router R2 learns from R1 that the link to the 192.168.1.0 network has been lost, R2 will respond by sending a route back to R1 with an infinite metric to the 192.168.1.0 network. E. R1 will send LSAs to R2 and R3 informing informing them of this change, and then all routers will send periodic updates at an increased rate o
C and D
5. What does the below output depicts? Router#debug Router#debug ip rip RIP protocol debugging is on Router# RIP: sending v2 update to 224.0.0.9 via Serial0 (20.0.0.2) RIP: build update entries 30.0.0.0/8 via 0.0.0.0, metric 1, tag 0 RIP: sending v2 update to 224.0.0.9 via Ethernet0 (30.0.0.1) RIP: build update entries 10.0.0.0/8 via 0.0.0.0, metric 2, tag 0 20.0.0.0/8 via 0.0.0.0, metric 1, tag 0 RIP: ignored v1 packet from 20.0.0.1 (illegal version) o
The above output depicts that the other end router is using RIPv1 and the routing protocol used on this router is RIPv2. As RIPv2 cannot receive version 1 by default, it is ignoring version1 packets sent by the router that is configured with RIPv1 R IPv1
Frame Relay - 49 -
HO
X
X
hor
bor
HO
Frame-relay switch Y
Y
Frame-relay is an example of a Packet Switched Network. This network enables
end-stations to dynamically share the existing connection (CIR) and an allowance Frame relay connections are often given a Committed Information Rate (CIR) (EIR ). The provider guarantees of burstable of burstable bandwidth known as the Extended Information Rate (EIR). that the connection will always support the CIR rate, and sometimes the EIR rate. Frames that are eligible" (DE) which means they can be dropped sent in excess of the CIR are marked as " discard eligible" when congestion occurs within the frame relay network. Frames sent in excess of the EIR are dropped immediately. Congestions in the network are reported by FECN=Forward Explicit Congestion Notification bit 1. FECN=Forward BECN=Backward Explicit Congestion Notification bit 2. BECN=Backward DE=Discard Eligibility bit provides the network with a signal to determine which 3. DE=Discard frames to be discarded, when there is a congestion on the line. The Frame-relay switch will discard frames with a DE value of 1 before discarding other frames.
R(config)#int R(config)#int s 0 R(config)#encapsula R(config)#encapsulation tion frame-relay // Defining // Defining the wan protocol
Once Encapsulation Frame-relay is given, serial interface requests the Frame-relay switch for the LMI type it uses and accordingly it changes. Then a DLCI is allocated to the l ink by the Frame Relay Switch. Then inverse arp maps destination ip address to the link’s DLCI No. .
Frame Relay mapping - 50 -
R3 S0
s1
100
200 20.0.0.1
20.0.0.2
R1
R2
R(config)#int S 0 R(config-if)#frame-relay map ip 20.0.0.2 100 broadcast Frame-relay mapping can be used in partially meshed topology or Hub & Spoke. If R1 wants to communicate with R2, which is not directly connected, we map R1 to R2 through the source DLCI number i.e, 100.
Point-to-point (Sub-interface) R3 Frame Switch
100
200
R1
R2
We can have multiple virtual circuits on a single serial interface, treating each and every single virtual circuit as a separate interface. This is achieved by creating sub interfaces in a Frame Relay network to avoid split horizon issues from preventing routing updates. We can configure separate sub interfaces for each PVC with a unique DLCI and subnet assigned to the sub interface. .
R3(config)#int S 0 R3(config-if)#no ip address R3(config-if)#exit R3(config)#int S 0.5 point-to-point // logically dividing the physical interface R3(config-subif)#ip address 20.0.0.1 255.0.0.0 // Assigning the IP address to the sub-interface R3(config-subif)#frame-relay interface-DLCI 100
- 51 -
Lab Setup :
Frame switch
S1 DCE 20 .0.0.1 S0
DTE E0
S0 DCE 20.0.0.2 S0
HOR
DTE E0 BOR
Step : 1 Configure Frame-Relay Switch FRSW (config)#Frame-relay switching Frsw(config)#int S 0 Frsw(config-if)#encapsulation frame-relay * Frsw(config-if)#frame-relay intf-type dce ** Frsw(config-if)#frame-relay route 100 int S 1 200 *** Frsw(config-if)#clock rate 64000 Frsw(config-if)#no shutdown Frsw(config)#int S 1 Frsw(config-if)#encapsulation frame-relay Frsw(config-if)#frame-relay intf-type dce Frsw(config-if)#frame-relay route 200 int S 0 100 Frsw(config-if)#clock rate 64000 Frsw(config-if)#no shutdown * FRSW (config-if )#encapsulation frame-relay ietf ( for non Cisco routers) ** By default Router’s serial interface is DTE. *** Routing the packets from S0 (DLCI=100) to S1 (DLCI no=200)
Step : 2 Configuring Head Office & Branch Office Routers
Configure HOR & BOR using routing protocols. Then HOR(config)#int s0 BOR(config)#int s0 HOR(config-if)#encapsulation frame-relay BOR(config-if)#encapsulation frame-relay
- 52 -
Step : 3 HOR#sh frame-relay map Serial0 (up): ip 20.0.0.2 dlci 100(0xC8,0x3080), dynamic, broadcast,, status defined, active BOR#sh frame-relay map Serial0 (up): ip 20.0.0.1 dlci 200(0xC8,0x3080), dynamic, broadcast,, status defined, active
Step : 4 Statically mapping - IP address to DLCI number (frame-mapping)
HOR(config)#int s0 HOR(config-if)#no frame-relay inverse-arp HOR(config-if)# ^z HOR#clear frame-relay-inarp
BOR(config)#int s0 BOR(config-if)#no frame-relay inverse-arp BOR(config-if)# ^z BOR#clear frame-relay-inarp
This will remove the dynamic address resolution done by Frame Relay Switch
HOR(config)#int s0 HOR(config-if)#frame-relay map ip 20.0.0.2 100 broadcast * BOR(config)#int s0 BOR(config-if)#frame-relay map ip 20.0.0.1 200 broadcast
* Here we are mapping Branch office IP address to the Head office DLCI number manually. If dynamic routing protocols are used, we use the keyword ‘broadcast’ .
Step : 5 HOR#sh frame-relay map Serial0 (up): ip 20.0.0.2 dlci 100(0xC8,0x3080), Static, broadcast,, status defined, active BOR#sh frame-relay map Serial0 (up): ip 20.0.0.1 dlci 200(0xC8,0x3080), Static, broadcast,, status defined, active
Step : 6 - 53 -
Creating Sub-interface
HOR(config)#int s0 HOR(config-if)#no ip address HOR(config-if)#exit HOR(config)#int s0.100 point-to-point HOR(config-subif)#ip address 20.0.0.1 255.0.0.0 HOR(config-subif)#frame-relay interface-dlci 100 BOR(config)#int s0 BOR(config-if)#no ip address BOR(config-if)#exit BOR(config)#int s0.200 point-to-point BOR(config-subif)#ip address 20.0.0.2 255.0.0.0 BOR(config-subif)#frame-relay interface-dlci 200
Commands
Router#sh frame-relay LMI To show frame-relay LMI type (CISCO, ANSI, Q933a)
Router#sh frame-relay PVC To show frame-relay PVC (Shows the FECN, BECN, DE, etc bits in the frame )
Router#sh frame-relay map To show frame-relay mapping (Shows the DLCI number assigned)
Outputs Router#sh frame-relay map Serial0 (up): ip 20.0.0.2 dlci 200(0xC8,0x3080), dynamic, broadcast,, status defined, active Router#sh frame-relay lmi LMI Statistics for interface Serial0 (Frame Relay DTE) LMI TYPE = CISCO Invalid Unnumbered info 0 Invalid Prot Disc 0 Invalid dummy Call Ref 0 Invalid Msg Type 0 Invalid Information ID 0 Invalid Report IE Len 0 Num Status Enq. Sent 13 Num Status msgs Rcvd 9
Router#sh frame-relay pvc - 54 -
PVC Statistics for interface Serial0 (Frame Relay DTE) Active Inactive Deleted Static Local 1 0 0 0 Switched 0 0 0 0 Unused 0 0 0 0 DLCI = 200, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0 input pkts 13 output pkts 12 in bytes 1104 out bytes 1090 dropped pkts 1 in FECN pkts 0 in BECN pkts 0 out FECN pkts 0 out BECN pkts 0 in DE pkts 0 out DE pkts 0 out bcast pkts 7 out bcast bytes 570 pvc create time 00:02:21, last time pvc status changed 00:02:01
Questions - 55 -
1 . What is frame-relay? o
Frame-relay is an example of a Packet Switched Network. This network enables endstations to dynamically use the available bandwidth and share the connection. Frame relay connections are often given a Committed Information Rate (CIR) and an allowance of burst able bandwidth known as the Extended Information Rate (EIR). Frames that are sent in excess of the CIR are marked as discard eligible(DE) which means they can be dropped when congestion occur in the network
2 . What is Link Management Interface (LMI)? o
LMI manages the link between frame switch and the router WAN port. Once the line is encapsulated to frame-relay, it requests frame switch which LMI it is using and accordingly WAN port also changes.
3 . Difference between Inverse ARP, ARP & RARP o o o
Inverse ARP helps to map destination IP address to local DLCI number at the frame Switch ARP helps to get the MAC address from the corresponding IP address. RARP helps to get the IP address from the corresponding MAC address
4 . What is DLCI (Data Link Connection Identifier)? o
The DLCI serves to identify the virtual connection so that the receiving end knows which information connection a frame belongs to.(Range=16 to 1007). This helps in Layer 2 identification.
5 . You are troubleshooting a frame relay connection and wish to view the LMI traffic status. Which command should you issue? o
Show frame-relay lmi
6 . When setting up Frame Relay for point-to-point subinterface, what should not be configured? o
An IP address on the physical interface.
7 . You need to configure a router for a Frame Relay connection to a non-Cisco - 56 -
router. Which command will prepare the WAN interface of the router for this connection? o
Router(config-if)#encapsulation frame-relay ietf
8 . How should a router that is being used in a Frame Relay network be configured to avoid split horizon issues from preventing routing updates? o
Configure a separate subinterface for each PVC with a unique DLCI and subnet assigned to the subinterface.
9 . What does the term ‘dynamic’ in the below output refers to : Router#sh frame-relay map Serial0 (up): ip 20.0.0.2 dlci 200(0xC8,0x3080), dynamic, broadcast,, status defined, active o
The mapping between DLCI 100 and the end station IP address 20.0.0.2 was through Inverse ARP
learned
10. In Frame Relay; what is the purpose of Inverse ARP? o
It is used to map a known DLCI to an IP address
11. By looking at the graphic below, what functions does the Frame Relay DLCI provide with respect to Router A?
DLCI 100 Router A
o
DLCI 200 RouterB
Router A would use DLCI 100 to get to the RouterB networks. RouterB would use DLCI 200 to get to the Router A networks.
12 . What does the STATUS=ACTIVE refers to in the output of the show frame-relay - 57 -
pvc command? Router#sh frame-relay pvc pvc statistics for interface serial0 (frame relay dte) dlci = 200, dlci usage = local, pvc status = active o
Active state - Indicates that the connection is active and that routers can exchange data. This is the state of an operational Permanent virtual Connection
13 . A default Frame Relay WAN is classified as what type of physical network? o
Non-broadcast multi-access
SWITCHING - 58 -
Trunk Port
Trunk Link Switches Hosts
Access Link
Would you like to start initial configuration [yes/no]: no Press return to get started Switch>enable Switch#configure terminal Switch (config) #int vlan 1 * By default all ports are in the VLAN1 Switch (config-if) #ip address 10.0.0.5 255.0.0.0 Switch (config-if) #no shutdown Switch (config-if) #exit Switch (config) #ip default gateway 10.0.0.1
Configuring different VLANs Switch (config) #vlan 2 Switch (config-vlan) #name finance Switch (config-vlan) #exit
// Creating the vlan
Switch (config) #vlan 3 Switch (config-vlan) #name production Switch (config-vlan) #exit [VLAN-no ranges from 2 to 1001] [VLAN name (xxx) is optional]
Allocating the ports to the VLANs Switch(config)#int f 0/1 Switch(config-if)#switchport access vlan 3 Switch(config-if)#exit Switch(config)#int f 0/2 Switch(config-if)#switchport access vlan 2 Switch(config-if)#exit Configuring the trunk Port - 59 -
// allocating ports to vlan
** Switch(config)#int f 0/24 Switch(config-if)#switchport mode trunk Switch(config-if)#exit
// creating the trunk port
By default, trunk port of the switch is in VLAN1. So this port should be configured as
trunk port to carry all Vlan information.
Domain Name Switch(config)#VTP domain Switch(config-if)#VTP domain MOHAN All the switches should be in the same domain
Switch’s operating mode
Switch(config)#VTP server/client/transparent
Commands - 60 -
1. Switch#sh MAC-address-table Displays the MAC address of the device and the corresponding port nos. to which the devices are connected. 2. Switch#sh vlan Displays the vlan information including port nos. that are in use, existing vlans & which port belongs to which vlan. 3. Switch#sh VTP status Displays configuration register, operating mode, domain name, etc.., 4. Switch#sh spanning-tree Displays priority, Root ID, Bridge ID, Mac address, Root Bridge
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OUTPUTS Switch#sh vlan VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4, Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/23, Fa0/24 1002 fddi-default act/unsup 1003 token-ring-default act/unsup 1004 fddinet-default act/unsup
SwX#sh vtp status
Switch#sh spanning-tree VLAN0001 Spanning tree enabled protocol ieee Root ID Priority 32769 Address 0014.a845.7280 This bridge is the root Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Bridge ID Priority 32769 (priority 32768 sys-id-ext 1) Address 0014.a845.7280 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 300 Interface Role Sts Cost Prio.Nbr Type ---------------- ---- --- --------- -------- -------------------------------Fa0/4 Desg FWD 100 128.4 Shr Fa0/17 Desg FWD 100 128.17 Shr
Intervlan Routing - 62 -
By default, only hosts that are within the same VLAN can communicate. To allow inter-VLAN
communication, we need a router or a layer 3 switch.
Intervlan switching using two fast Ethernet interfaces of the Router Router
f 0/0
f 0/4 PC 1
f 0/1
Switch
f 0/3
f 0/9 PC 2 f 0/8
IP address: 10.1.0.10 SNM : 255.255.0.0 DG : 10.1.0.1 Vlan 2
IP address: 10.2.0.10 SNM : 255.255.0.0 DG : 10.2.0.1 Vlan 3
Configuring Switch Switch(config)#vlan 2 Switch(config-vlan)#name Fin
Switch(config)#vlan 3 Switch(config-vlan)#name mktg
Allocating Ports Switch(config)#int f0/3 Switch(config-if)#switchport access vl 2 Switch(config)#int f0/4 Switch(config-if)#switchport access vl 2
Switch(config)#int f0/8 Switch(config-if)#switchport access vl 3 Switch(config)#int f0/9 Switch(config-if)#switchport access vl 3
Configuring Router Router(config)#int f0/0 Router (config-if)#ip add 10.1.0.1 255.255.0.0 Router (config-if)#no shutdown Router(config)#int f0/1 Router (config-if)#ip add 10.2.0.1 255.255.0.0 Router (config-if)#no shutdown
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Intervlan communication using single fast Ethernet interface of the Router is achieved by creating sub interfaces. Router
f 0/0 f 0/5 PC 1
f 0/3
f 0/8
IP address: 10.1.0.10 SNM : 255.255.0.0 DG : 10.1.0.1 Vlan 2
PC 2 IP address: 10.2.0.10 SNM : 255.255.0.0 DG : 10.2.0.1 Vlan 3
Configuring Switch Switch(config)#vlan 2 Switch(config-vlan)#name Fin
Switch(config)#vlan 3 Switch(config-vlan)#name mktg
Allocating Ports Switch(config)#int f0/3 Switch(config-if)#switchport access vl 2 Switch(config)#int f0/5 Switch(config-if)#switchport mode trunk
Configuring Router Router(config)#int f0/0 Router (config-if)#no ip address Router (config-if)#no shutdown Router (config-if)#exit Router(config)#int f0/0 .1 Router(config-subif)#encapsulation dot1q Router(config-subif)#encapsulation dot1q 2 Router(config-subif)#ip add 10.1.0.1 255.255.0.0 Router(config)#int f0/0 .2 Router(config-subif)#encapsulation dot1q Router(config-subif)#encapsulation dot1q 3 Router(config-subif)#ip add 10.2.0.1 255.255.0.0
- 64 -
Switch(config)#int f0/8 Switch(config-if)#switchport access vl 3
Questions
1. Difference between Switch and Hub? Switch
Hub
Switch is a layer-2 component
Hub is a layer-1 component
Switch learn MAC address
Hub doesn’t learn MAC address
Has one Broadcast Domain
Has one Broadcast domain
Has multiple collision domain
Has only one collision domain
2 . Different forwarding trends in switch? o
o
o
Store & forward-- stores the frame, checks for the errors and forwards only the error free frames. Cut-through – No error checking; just receives and forwards the frames. Fragment free – is also called as Modified Cut-through. The minimum ip packet size st is of 64 bytes. The 1 64 bytes of frame is checked for errors, where this 64 bytes include the frame header, Destination MAC add (DMAC), Source MAC add (SMAC) and some data. So, if these 64 bytes seem to be a good frame set then it is forwarded or else it dumps the packets.
3 . Facts of Vlans o o o o o o
Vlan is created to avoid unnecessary broadcasts Vlans are created without changing the physical set up By default each switch is in vlan 1 Only systems in same vlan will communicate For inter-vlan communication we need Router/Layer 3 Switch VLAN setup is controlled by VTP(VLAN Trunk Protocol)
4 . Difference between Access link and Trunk link? Systems are connected to the switch through the access link and the switches are connected each other through the trunk links. o
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5 . Different Operating modes in switch? o
o
o
Server — By default, all switches are in Server mode.Vlans can configured in created in this mode. Clients — No changes can be made in client mode. Transparent — will not take any condition; it just forwards the conditions to the other switches.
6. Why spanning-tree Protocol is used? o
Spanning-tree Protocol is been run to avoid the routing loops in a switched network. It elects the Root Bridge and the Non-Root Bridge with the help of bpdu. The one with the lesser bpdu will be elected as the Root Bridge. Root Bridge will be having every port in forwarding mode of a frame on interface.
7 . What does a switch do when it receives a frame on interface and destination address is unknown? o
It floods the network with the frame looking for the device
8 . How to manually elect a switch as root bridge? o
We could manually elect a switch as root bridge by changing the priority as Switch(config)#spanning-tree vlan1 priority
8 . Different Spanning-tree port states? o o o o o
Blocking: It won’t forward frames, pr event looping and by defaults all ports are blocked. Listening: Listens no loop has formed on N/W before passing frame. Learning: Listens and learns all paths in the N/W and updates MAC table. Forwarding: Sends and receives frames. Disabled: Does not participate in forwarding frame.
9 . What are the different functions of Switch? o
o
o
Address Learning: Learns the source hardware/Mac address of each frame received and stores it in MAC address table. Forwarding/Filtering Decision: When received a frame on an interface, switch looks the destination hardware address and finds the exit interface in the MAC table. Loop Avoidance: When more connection are made on switch for redundancy, BC loops occur. Spanning-tree Protocol is used to stop BC loops.
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10 . What is the result of segmenting a network with a switch? It increases the number of collision domains and will be smaller collision domains
o
11 . What will occur if two Cisco LAN switches are connected with a single crossover cable? The switch port link lights will be green, indicating normal operation.
o
12 . What are the three distinct functions of layer 2 switching that increase available bandwidth on the network?
Address learning Forwarding and filtering Loop avoidance o
A
13 . What technology is used by Catalyst switches to resolve topology loops and ensure that data flows properly through a single network path? o
Spanning Tree Protocol (STP )
14 . Your core switch needs to be set as the root bridge of your network. What will make our core switch the root bridge? o
Setting the bridge priority to less than 32,768
15 . What purpose in a switched LAN does STP perform? o
Prevent switching loops in a network with redundant switched paths.
16 . Which LAN switch type waits for the collision window to pass before looking up the destination hardware address in the MAC filter table and forwarding the frame? o
Fragment Free looks at the first 64 bytes of a frame to make sure a collision does not occur. It is sometimes referred to as modified cut-through.
17 . When a new trunk link is configured on an IOS-based switch, which VLANs are allowed over the link? o
By default, all Vlans are allowed on the trunk.
18 . What VTP mode allows you to change VLAN information on the switch? o
Server
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19 . These two switches are not sharing VLAN information. From the output below, what is the reason. why these switches are not sharing VTP messages? SwitchA#sh vtp status VTP Version :2 Configuration Revision :0 Maximum VLANs supported locally : 64 Number of existing VLANs :7 VTP Operating Mode : Server VTP Domain Name : RouterSim VTP Pruning Mode : Disabled SwitchB#sh vtp status VTP Version :2 Configuration Revision :1 Maximum VLANs supported locally : 64 Number of existing VLANs :7 VTP Operating Mode : Server VTP Domain Name : GlobalNet VTP Pruning Mode : Disabled The VTP domain names are not configured correctly.
o
20 . What is the benefit of creating Vlans? o o o
They allow logical grouping of users by function. They can enhance network security. They increase the number of broadcast domains while decreasing the size of the Broadcast domains. A
21 . How many broadcast domain exist in the exhibited topology?
o
Three
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VIRTUAL PRIVATE NETWORK (VPN)
A virtual private network (VPN) allows the creation of private networks across the Internet. VPNs are used daily to give remote users and disjointed networks connectivity over a public medium like the Internet instead of using more expensive permanent means. Virtual private network is a method of encrypting point-to-point logical connections across a public network, such as the Internet. This allows secure communications across a public network.
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Questions 1. What are the two security appliances that can be installed in a network? (choose 2) A. B. C. D. E. F.
ATM (Asynchronous Transfer Mode) IDS (Intrusion Detection System) IOS (Internetwork Operating System) IOX IPS (Intrusion Prevention System) SDM (Security Device Manager)
o
B and E
2. What are the 3 typical categories of VPNs? Remote access VPNs Site-to-site VPNs Extranet VPNs Remote access VPNs allow remote users like telecommuters to securely access the corporate
network wherever and whenever they need to.
Site-to-site VPNs or intranet VPNs, allow a company to connect its remote sites to the corporate backbone securely over a public medium like the Internet instead of requiring more expensive WAN connections like Frame Relay.
Extranet VPNs allow an organization’s suppliers, partners, and customers to be connected to the corporate network in a limited way for business-to-business (B2B) communications. 3. To provide security in your VPN tunnel, what protocol suite would you use? o
IPSec
IPSec is an industry-wide standard suite of protocols and algorithms that allows for secure data transmission over an IP-based network that functions at the layer 3 Network layer of the OSI model.
4. Which of the following describes the creation of private networks across the Internet, enabling privacy and tunneling of non-TCP/IP protocols? A. HDLC B. Cable C. VPN D. IPSec E. xDSL o
C
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Internet Protocol Version 6 (IPv6)
Ipv4 is a 32 bit addressing scheme, whereas IPv6 is a 128 bit hexa decimal addressing scheme, represented in 8 combinations of 4 hexa decimal numbers each separated by a colon. Hence IPV6 is called a 16-bit Hexadecimal Colon-delimited Block.
Representation: An IPV6 address is represented as shown below:
2003:1234:ABCD:0001:5678:DCBA:4321:EFGH
Global Unicast
Interface ID Subnet
Global Prefix 1. Global Unicast recognizes the particular Region or Zone. It is a publicly routable address. 2. Global Prefix is provided by ISP, it’s of 48 bits. 3. Subnet tells you to which particular organization it belongs. 4. Interface id is of 64 bits, where the 48 bit MAC address is padded with FFFE which is of 16 bits and is placed exactly in the middle of the MAC address to make it a 64 bit interface id.
Ex: 2000:12ab:34cd:00ef:1234:4295:0000:00cd In the above expression ‘00ef ‘ can be represented as ‘ef ‘ and the continuous z eros can be
replaced by double colons( :: ).It can be re-written as 2000:12ab:34cd:ef:1234:4295::cd
Ex : 2000:0000:0000:00ef:1234:kf34:eef0:cd4e
=> 2000::ef: 1234:kf34:eef0:cd4e
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Ex : 2001:0000:0000:0012:0000:0000:1234:56ab
And you can’t do this: 2001::12::1234:56ab Instead, the best way you can do is 2001::12:0:0:1234:56ab
Difference between IPv4 & IPv6:
0:0:0:0:0:0:0:0 This is the equivalent of IPv4’s 0.0.0.0 0:0:0:0:0:0:0:1 The equivalent of 127.0.0.1 in IPv4 2000::/3 The global Unicast address range. FC00::/7 The unique local Unicast range. FE80::/10 The link-local Unicast range. FF00::/8 The multicast range. 3FFF:FFFF::/32 Reserved for examples and documentation. 2001:0DB8::/32 Also reserved for examples and documentation.
Extended Uniform Identification (eui-64): You can specify the entire 128-bit global IPv6 address or you can use the eui-64 option. The eui-64 format allows the device to use its MAC address and pad it to m ake the interface ID. Router(config-if)#ipv6 address 2001:db8:3c4d:1::/64 eui-64 The Globe is divided into 5 Zones and each zone will be assigned a number range to i dentify them. Here the ‘/64’ represents the identification of the Zone and the IP of the company in that zone.Eui 64 will pad an extra FFFE to the MAC address exactly to its center.
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E.g. MAC address 0060.d673.1987 after padding would look like – 0260.d6ff.fe73.1987 In the above e.g. 0 0000
0 0000
6
0
D
6
7
3
1
9
8
7
th
7 bit is 0 then the address is locally unique. 0 2 6 0 D 6 0000 0010
F F F E
7 3 1 9 8 7
th
After padding the 7 bit changes to 1, now the address is Link local address. It is globally unique address. This padding process is called as EUI-64 i.e. Extended Uniform Identifier. EUI-64 is an IEEE standard that is given to the MAC address of any particular system where eve ry system’s MAC address will be automatically assigned. MAC address is the part of IPV6 address which makes it a unique address.
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LAB
DTE E0
DCE S0 E0
S0 R1
R2
R1(config)#ipv6 unicast-routing // By default ipv6 is disabled R1(config)#int e0 R1(config-if)#ipv6 add 2004:abcd:1234:0001::/64 eui-64 R1(config-if)#ipv6 rip 1 enable R1(config-if)#no shutdown R1(config)#int s0 R1(config-if)#ipv6 add 2005:abcd:1234:0002::/64 eui-64 R1(config-if)#ipv6 rip 1 enable R1(config-if)#no shutdown R2(config)#ipv6 unicast-routing R2(config)#int e0 R2(config-if)#ipv6 add 2003:abcd:1234:0001::/64 eui-64 R2(config-if)# ipv6 rip 1 enable R2(config-if)#no shutdown R2(config)#int s0 R2(config-if)#ipv6 add 2005:abcd:1234:0002::/64 eui-64 R2(config-if)#no shutdown R2(config-if)# ipv6 rip 1 enable R2(config-if)#clock rate 64000
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Outputs
R2#sh ipv6 int brief
Ethernet0 [up/up] FE80::210:7BFF:FE7F:B8EA 2003:ABCD:1234:1:210:7BFF:FE7F:B8EA Serial0 [up/up] FE80::210:7BFF:FE7F:B8EA 2005:ABCD:1234:2:210:7BFF:FE7F:B8EA Serial1 [administratively down/down]
For each interface IPv6 will create a Link local & Global Unicast address.
Global unicast addresses These are publicly routable addresses, and they’re the same as they are in IPv4. Link-local addresses These are like the private addresses in IPv4, that means they’re not routable on a public network. R2#sh ipv6 int e0 Ethernet0 is up, line protocol is up IPv6 is enabled, link-local address is FE80::210:7BFF:FE7F:B8EA Global unicast address(es): 2003:ABCD:1234:1:210:7BFF:FE7F:B8EA, subnet is 2003:ABCD:1234:1::/64 Joined group address(es): FF02::1 FF02::2 FF02::1:FF7F:B8EA MTU is 1500 bytes
R2#sh ipv6 int s0 Serial0 is up, line protocol is up IPv6 is enabled, link-local address is FE80::210:7BFF:FE7F:B8EA Global unicast address(es): 2005:ABCD:1234:2:210:7BFF:FE7F:B8EA, subnet is 2005:ABCD:1234:2::/64 Joined group address(es): FF02::1 FF02::2 FF02::1:FF17:2 FF02::1:FF7F:B8EA MTU is 1500 bytes
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R2#sh ipv6 route ( without configuring RIP ) IPv6 Routing Table - 6 entries Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP C 2003:ABCD:1234:1::/64 [0/0] via ::, Ethernet0 L 2003:ABCD:1234:1:210:7BFF:FE7F:B8EA/128 [0/0] via ::, Ethernet0 C 2005:ABCD:1234:2::/64 [0/0] via ::, Serial0 L 2005:ABCD:1234:2:210:7BFF:FE7F:B8EA/128 [0/0] via ::, Serial0 L FE80::/10 [0/0] via ::, Null0 L FF00::/8 [0/0] via ::, Null0
R2#sh ipv6 route (configuring RIP )
IPv6 Routing Table - 6 entries Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP U - Per-user Static route I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary C 2003:ABCD:1234:1::/64 [0/0] via ::, Ethernet0 L 2003:ABCD:1234:1:210:7BFF:FE7F:B8EA/128 [0/0] via ::, Ethernet0 R 2004:abcd:1234:1::/64 [120/2] Via FE80::200:CFF:FE91:811E, serial 0 C 2005:ABCD:1234:2::/64 [0/0] via ::, Serial0 L 2005:ABCD:1234:2:210:7BFF:FE7F:B8EA/128 [0/0] via ::, Serial0 L FE80::/10 [0/0] via ::, Null0 L FF00::/8 [0/0] via ::, Null0
R2#debug ipv6 rip
RIP Routing Protocol debugging is on R2# RIPng: response received from FE80::200:CFF:FE91:811E on Serial0 for 1 src=FE80::200:CFF:FE91:811E (Serial0) …….. Multicast address dst=FF02::9 sport=521, dport=521, length=52 command=2, version=1, mbz=0, #rte=2 tag=0, metric=1, prefix=2003:ABCD:1234:2::/64 tag=0, metric=1, prefix=2003:ABCD:1234:3::/64 - 76 -
RIPng: Sending multicast update on Ethernet0 for 1 src=FE80::210:7BFF:FE7F:B8EA dst=FF02::9 (Ethernet0) sport=521, dport=521, length=72 command=2, version=1, mbz=0, #rte=3 tag=0, metric=1, prefix=2003:ABCD:1234:1::/64 tag=0, metric=1, prefix=2003:ABCD:1234:2::/64 tag=0, metric=2, prefix=2003:ABCD:1234:3::/64 RIPng: Sending multicast update on Serial0 for 1 src=FE80::210:7BFF:FE7F:B8EA dst=FF02::9 (Serial0) sport=521, dport=521, length=52 command=2, version=1, mbz=0, #rte=2 tag=0, metric=1, prefix=2003:ABCD:1234:1::/64 tag=0, metric=1, prefix=2003:ABCD:1234:2::/64
Dual Stacking : It allows our devices to communicate using either IPv4 or IPv6. It’ll look something li ke this: Router(config)#ipv6 unicast-routing Router(config)#interface fastethernet 0/0 Router(config-if)#ipv6 address 2001:db8:3c4d:1::/64 eui-64 Router(config-if)#ip address 192.168.255.1 255.255.255.0
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Questions
1. How long is an IPv6 address? A. 32 bits B. 128 bytes C. 64 bits D. 128 bits D
2. To enable RIPng, which of the following would you use? A. Router1(config-if)# ipv6 ospf 10 area 0.0.0.0 B. Router1(config-if)#ipv6 rip 1 enable C. Router1(config)# ipv6 router eigrp 10 D. Router1(config-rtr)#no shutdown E. Router1(config-if)#ipv6 eigrp 10 B
3. What two statements about IPv6 addresses are true? (Choose two.) A. Leading zeros are required. B. Two colons (::) are used to represent successive hexadecimal fields of zeros. C. Two colons (::) are used to separate fields. D. A single interface will have multiple IPv6 addresses of different t ypes. B,D
4. What two statements about IPv4 and IPv6 addresses are true? A. An IPv6 address is 32 bits long, represented in hexidecimal. B. An IPv6 address is 128 bits long, represented in decimal. C. An IPv4 address is 32 bits long, represented in decimal. D. An IPv6 address is 128 bits long, represented in hexidecimal. C,D
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WIRELESS LAN (WLAN)
1. A single 802.11g access point has configured and installed in the center of a square office. A few wireless users are experiencing slow performance and drops while most users are operating at peak efficiency. What are three likely causes? A. mismatched TKIP encryption B. cordless phones C. mismatched SSID D. metal file cabinets E. antenna type or direction B,D,E
2. Which two statements best describe the wireless security standard that is defined by WPA? (Choose two.) A. It specifies use of a static encryption key that must be changed frequently to enhance security. B. It requires use of an open authentication method. C. It specifies the use of dynamic encryption keys that change each time a client establishes a connection. D. It requires that all access points and wireless devices use the same encryption key. E. It includes authentication by PSK. C, E
3. You and a co-worker have established wireless communication directly between your wireless laptops. What type of wireless topology has been created? A. BSS B. ESS C. IBSS D. SSID C
4. Which two devices can interfere with the operation of a wireless network because they operate on similar frequencies? (Choose two.) A. copier B. microwave oven C. toaster D. cordless phone E. IP phone B, D
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5. What is the maximum data rate specified for IEEE 802.11b WLANs? A. 10 Mbps B. 11 Mbps C. 54 Mbps D. 100 Mbps B
6. Which spread spectrum technology does the 802.11b standard define for operation? A. IR B. DSSS C. FHSS D. DSSS and FHSS E. IR, FHSS and DSSS B
7. What is one reason that WPA encryption is preferred over WEP? A. A WPA key is longer and requires more special characters than the WEP key. B. The access point and the client are manually configured with different WPA key values. C. WPA key values remain the same until the client configuration is changed. D. The values of WPA keys can change dynamically while the system is used. D
8. What two facts can be determined from the WLAN diagram (choose 2)?
A. B. C. D. E.
The area of overlap of the two cells represents a basic service set (BSS) The network diagram represents an extended service set (ESS) Access points in each cell must be configured to use channel 1 The area of overlap must be less than 10% of the area to ensure connectivity The two APs should be configured to operate on different channels
B and E
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BOOTING
1. Refer to the exhibit. For what two reasons has the router loaded its IOS image from the location that is shown(choose two)?
A. B. C. D. E.
Router 1 has specific boot system commands that instruct it to load IOS from a TFTP server Router 1 is acting as a TFTP server for other routers. Router 1 cannot locate a valid IOS image in the flash memory. Router 1 defaulted to ROMMON mode and loaded the IOS image from a TFTP server. Cisco routers will first attempt to load an image from TFTP for management purpose
A and C
2. During startup, the router displays the following error message. Boot cannot open “flash”. What will the router do next? A. B. C. D.
because of damaged flash memory, router will fail the POST. It will attempt to locate the IOS from a TFTP server, if it fails it will initiate the setup dialog. It will attempt to locate the IOS from a TFTP server, it will load a limited IOS from ROM. It will attempt to locate the configuration file from a TFTP server, if it fails it will initiate the setup dialog E. It will attempt to locate the configuration file from a TFTP server, if it fails it will load a limited configuration from ROM C
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3. When upgrading the IOS image, the network administrator receives the exhibited Error message. What could be the cause of error?
A. B. C. D. E.
The new IOS image is too large for the router flash memory. The TFTP server is unreachable from the router The new IOS is not correct for this router platform. The IOS image on the TFTP server is corrupt. There is not enough disk space on the TFTP server for the IOS image.
B
4. There are no boot system commands in a router configuration in NVRAM. What is the fallback sequence that the router will use to find an IOS during reload? A. B. C. D. E.
TFTP server,Flash,NVRAM ROM,NVRAM,TFTP server NVRAM,TFTP server,ROM Flash,TFTP server
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