Tài liệu EIGRP Troubleshooting pptx

Scenario You have been asked to check out the Westasman, SanJose1 and Eastasman routers.. It has been determined that workstations connected to the Westasman router cannot communicate w

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Lab 12.2.1.1 EIGRP Troubleshooting

F0/0 192.168.0.1/24

S0/1 192.168.112.1/24 S0/0 192.168.64.1/30

S0/0 192.168.64.2/30 S0/1 192.168.112.2/24

Fa0/0 192.168.72.1/24 Fa0/0 192.168.120.1/24

SanJose1

Objective

Utilize a systematic approach to troubleshoot a simple network problem

Scenario

You have been asked to check out the Westasman, SanJose1 and Eastasman routers It has been determined that workstations connected to the Westasman router cannot communicate with users on the SanJose1 or Eastasman routers The workstations on the Eastasman router cannot communicate with either the Westasman or SanJose1 workstations

Lab Tasks

Build the network according to the diagram above and load the appropriate

‘broken’ configuration files to each router Save the configurations and reload each router Clock rates have been applied to all serial interfaces

Step 1

Define your problem

Users report that they are unable to communicate with workstations on remote networks Users on the same network are able to communicate with each other

Step 2

Gather the Facts

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Based on the current information you have, all the evidence points to a WAN link failure You then login to the routers to gather more information about the problem

Issue the following commands to narrow down your possibilities

The first thing to check is your connections

SanJose1#show ip interface brief

Interface IP-Address OK? Method Status Protocol FastEthernet0/0 192.168.0.1 YES manual up up Serial0/0 192.168.112.1 YES manual up up Serial0/1 192.168.64.2 YES manual up up

Eastasman#show ip interface brief

Interface IP-Address OK? Method Status Protocol FastEthernet0/0 192.168.120.1 YES manual up up Serial0/0 192.168.112.2 YES manual up up BRI0/0 unassigned YES unset administratively down down BRI0/0:1 unassigned YES unset administratively down down BRI0/0:2 unassigned YES unset administratively down down FastEthernet0/1 unassigned YES unset administratively down down Serial0/1 unassigned YES unset administratively down down

Westasman#show ip interface brief

Interface IP-Address OK? Method Status Protocol FastEthernet0/0 192.168.72.1 YES manual up up Serial0/0 192.168.64.1 YES manual up up BRI0/0 unassigned YES unset administratively down down BRI0/0:1 unassigned YES unset administratively down down BRI0/0:2 unassigned YES unset administratively down down Serial0/1 unassigned YES unset administratively down down Then check the routing table to see if you have the appropriate routes Note –

in a very large network you can enter a network number to limit the display

SanJose1#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

E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP

i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area

* - candidate default, U - per-user static route, o - ODR

P - periodic downloaded static route

Gateway of last resort is not set

192.168.64.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.64.0/30 is directly connected, Serial0/1

C 192.168.0.0/24 is directly connected, FastEthernet0/0

Eastasman#show ip route

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Westasman#show ip route

EIGRP log-neighbor-changes is the best tool you have to diagnose un-stable neighbor relationships You may want to enable it on every router in your network The uptime value from show ip eigrp neighbors will tell you the

last time a neighbor relationship was reset (bounced), but not how often or why With log-neighbor-changes on and logging buffered , you keep not only a history of when neighbors have been reset, but the reason why

Logging buffered is also recommended because logging to a syslog server

is dependent on the network For example, if the neighbor bouncing is between the router losing neighbors and the syslog server, the messages could be lost

It may be prudent to keep these types of messages locally on the router

It may also be useful to increase the size of the buffer log in order to capture a greater duration of error messages You would hate to lose the EIGRP

neighbor messages because of flapping links filling the buffer log If your

routers have enough memory to hold the log file, change the buffer log size us-ing the command logging buffered {value} in configuration mode

SanJose1(config)#router eigrp 123

SanJose1(config-router)#eigrp log-neighbor-changes

SanJose1(config-router)#exit

SanJose1(config)#logging buffered 4096

02:09:15: %DUAL-5-NBRCHANGE: IP-EIGRP 123: Neighbor 192.168.64.1 (Serial0/1) is up:

new adjacency 02:09:16: %DUAL-5-NBRCHANGE: IP-EIGRP 123: Neighbor 192.168.64.1 (Serial0/1) is down:

holding time expired 02:09:16: %DUAL-5-NBRCHANGE: IP-EIGRP 123: Neighbor 192.168.112.2 (Serial0/0) is up:

holding time expired

Step 3

Consider the possibilities Use the information you have and your knowledge of Cisco products to isolate the problem

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Neighbor relationships are flapping Possible configuration error within the rout-ing protocol Check routrout-ing information

Step 4

Create an action plan

Confirm the configuration of the EIGRP routing protocol Change configurations

as necessary

Step 5

Implement the action plan

Confirm the configuration of eigrp 123 on the routers Note – the following command can be used to parse the output of the running configuration

SanJose1#show run | begin router eigrp

router eigrp 123

network 192.168.0.0

network 192.168.64.0 0.0.0.3

network 192.168.112.0

no auto-summary

eigrp log-neighbor-changes

!

ip classless

no ip http server

!

banner motd ^CCLab 12-1^C

!

line con 0

password 7 030752180500

login

transport input none

line aux 0

line vty 0 4

password 7 070C285F4D06

login

!

no scheduler allocate

end

Eastasman#show run | begin router eigrp

router eigrp 123

network 192.168.112.0

network 192.168.120.0

no auto-summary

!

ip classless

no ip http server

!

line con 0

password 7 110A1016141D

login

line aux 0

line vty 0 4

password 7 14141B180F0B

login

!

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end

Westasman#show run | begin router eigrp

router eigrp 123

network 192.168.64.0 0.0.0.3

network 192.168.72.0

no auto-summary

!

ip classless

no ip http server

!

line con 0

exec-timeout 0 0

password cisco

login

line aux 0

line vty 0 4

password cisco

login

!

end

Everything looks fine here

Now check the hello-interval and hold-time on each interface Note – on core routers with long configurations, parsing output will always help to reduce the information displayed

SanJose1#show run interface s0/0

Building configuration

Current configuration : 179 bytes

!

interface Serial0/0

ip address 192.168.112.1 255.255.255.0

ip hello-interval eigrp 123 10

ip hold-time eigrp 123 1

encapsulation ppp

no ip mroute-cache

no fair-queue

end

SanJose1#show run interface s0/1

Current configuration : 145 bytes

!

interface Serial0/1

ip address 192.168.64.2 255.255.255.252

encapsulation ppp

end

Westasman#show run interface s0/0

Current configuration:

!

interface Serial0/0

ip address 192.168.64.1 255.255.255.252

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no ip directed-broadcast

encapsulation ppp

no ip mroute-cache

no fair-queue

clockrate 56000

end

Eastasman#show run interface s0/0

Current configuration:

!

interface Serial0/0

ip address 192.168.112.2 255.255.255.0

no ip directed-broadcast

encapsulation ppp

no ip mroute-cache

no fair-queue

clockrate 56000

end

Based on your knowledge of EIGRP, you know that the hello-interval and the hold-time for the SanJose1 router is incorrectly configured A general rule is to set the hello-interval to 180 seconds on slow WAN links and the hold-time to 3 times the hello-interval, which would be 540 seconds

Issue the following commands to remedy the situation

SanJose1(config)#interface s0/0

SanJose1(config-if)#ip hello-interval eigrp 123 180

SanJose1(config-if)#ip hold-time eigrp 123 540

SanJose1(config)#interface s0/1

SanJose1(config-if)#ip hello-interval eigrp 123 180

SanJose1(config-if)#ip hold-time eigrp 123 540

Step 6

Observe the Results of the action plan

Login to each router Check if the routing tables are being populated properly Also, perform an extended ping from end to end

Issue the show ip route command:

SanJose1#show ip route

D 192.168.72.0/24 [90/20514560] via 192.168.64.1, 00:01:00, Serial0/1

D 192.168.120.0/24 [90/20514560] via 192.168.112.2, 00:00:18, Serial0/0

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Westasman#show ip route

D 192.168.120.0/24 [90/21026560] via 192.168.64.2, 00:01:01, Serial0/0

D 192.168.112.0/24 [90/21024000] via 192.168.64.2, 00:02:31, Serial0/0

D 192.168.112.2/32 [90/21024000] via 192.168.64.2, 00:02:31, Serial0/0

D 192.168.0.0/24 [90/20514560] via 192.168.64.2, 00:02:31, Serial0/0

Eastasman#show ip route

D 192.168.72.0/24 [90/21026560] via 192.168.112.1, 00:01:35, Serial0/0

D 192.168.64.0/30 [90/21024000] via 192.168.112.1, 00:01:35, Serial0/0

D 192.168.64.1/32 [90/21024000] via 192.168.112.1, 00:01:35, Serial0/0

D 192.168.0.0/24 [90/20514560] via 192.168.112.1, 00:01:35, Serial0/0

Issue an extended ping command to test end-to-end connectivity:

Eastasman#ping

Protocol [ip]: ip

Target IP address: 192.168.72.1

Repeat count [5]:

Datagram size [100]:

Timeout in seconds [2]:

Extended commands [n]: y

Source address or interface: 192.168.120.1

Type of service [0]:

Set DF bit in IP header? [no]:

Validate reply data? [no]:

Data pattern [0xABCD]:

Loose, Strict, Record, Timestamp, Verbose[none]:

Sweep range of sizes [n]:

Type escape sequence to abort

Sending 5, 100-byte ICMP Echos to 192.168.72.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 72/77/96 ms

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Step 7

Document your work

Tiêu đề	Lab 12.2.1.1 EIGRP Troubleshooting
Chuyên ngành	Computer Networking
Thể loại	Lab
Năm xuất bản	2001

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