Tài liệu OSPF Troubleshooting pptx

Scenario Your company has implemented OSPF as its core routing protocol.. The Frankfurt and Berlin routers connect the company’s core to legacy RIP networks that will eventually be migr

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Lab 13.2.1.1: OSPF Troubleshooting

F0/0 192.168.72.1/24

S0/1 192.168.10.5/30 S0/0 192.168.10.14/30

Fa0/0 10.0.1.1/24 Fa0/0 10.0.4.1/24

Westasman

OSPF Area 0

S0/0 192.168.10.10/30

S0/0 192.168.10.9/30

RIP v2 RIP v2

Lo0/0 10.0.2.1/24

Lo0/1 10.0.3.1/24

Objective

Utilize a systematic troubleshooting method on an OSPF network

Scenario

Your company has implemented OSPF as its core routing protocol All inter-faces on the Westasman router belong to OSPF area 0 The Frankfurt and Berlin routers connect the company’s core to legacy RIP networks that will eventually be migrated to OSPF, but must continue to use RIP until older

routers are replaced (The RIP networks, which include many of the company’s routers, are represented in this lab scenario by Ethernet and Loopback inter-faces on the Frankfurt and Berlin routers.)

After the partial change to OSPF, users connected to the Westasman router report that they are unable to communicate with users connected to Frankfurt and Berlin Your task is to troubleshoot and correct this problem

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

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Confirm connectivity by performing pings between routers All pings should be successful

Step 1

Define the problem you are experiencing

Users connected to the Westasman router report that they are unable to com-municate with any servers connected to the Berlin and Frankfurt routers You already verified that it is not a workstation issue

Step 2

Gather relevant facts about the situation Upon examining the router, what fac-tual information can you obtain from the router?

Login to the Westasman router and perform basic connectivity tests

Ping the WAN interface of Berlin

Westasman#ping 192.168.10.13

Type escape sequence to abort

Sending 5, 100-byte ICMP Echos to 192.168.10.13, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 36/42/60 ms

Ping the LAN interface of Berlin

Success rate is 0 percent (0/5)

Ping the WAN interface of Frankfurt

!!!!!

Ping the LAN interface of Frankfurt

Success rate is 0 percent (0/5)

Examine the routing table of Westasman

Westasman#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

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Gateway of last resort is not set

C 192.168.72.0/24 is directly connected, FastEthernet0/0

192.168.10.0/30 is subnetted, 3 subnets

C 192.168.10.4 is directly connected, Serial0/1

O 192.168.10.8 [110/1562] via 192.168.10.6, 01:04:47, Serial0/1

[110/1562] via 192.168.10.13, 01:04:47, Serial0/0

Notice there are no routes to any of the RIP networks

Step 3

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

Based on the information you gathered so far, the problem seems to be within the routing protocol RIP may not be redistributing into OSPF

Step 4

Formulate an action plan to solve this problem

Gather more information about neighboring routers Check if redistribution is setup properly Modify configurations as necessary

Step 5

Implement your action plan and attempt to fix the problem Log all changes made

Examine the interfaces and routing tables of neighboring routers

Berlin#show ip interface brief

Interface IP-Address OK? Method Status Protocol FastEthernet0/0 10.0.1.1 YES NVRAM up up Serial0/0 192.168.10.13 YES NVRAM up up BRI0/0 unassigned YES NVRAM administratively down down BRI0/0:1 unassigned YES unset administratively down down BRI0/0:2 unassigned YES unset administratively down down Serial0/1 192.168.10.10 YES NVRAM up up Loopback0 10.0.2.1 YES NVRAM up up Loopback1 10.0.3.1 YES NVRAM up up

Berlin#show ip route

O 192.168.72.0/24 [110/782] via 192.168.10.14, 01:23:27, Serial0/0

O 192.168.10.4 [110/1562] via 192.168.10.9, 01:23:27, Serial0/1

[110/1562] via 192.168.10.14, 01:23:27, Serial0/0

C 10.0.2.0 is directly connected, Loopback0

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C 10.0.1.0 is directly connected, FastEthernet0/0

Frankfurt#show ip interface brief

Interface IP-Address OK? Method Status Protocol

FastEthernet0/0 10.0.4.1 YES NVRAM up up

Serial0/0 192.168.10.6 YES NVRAM up up

BRI0/0 unassigned YES NVRAM 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 NVRAM administratively down down

Serial0/1 192.168.10.9 YES NVRAM up up

Frankfurt#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 O 192.168.72.0/24 [110/782] via 192.168.10.5, 01:24:32, Serial0/0 192.168.10.0/30 is subnetted, 3 subnets C 192.168.10.4 is directly connected, Serial0/0 C 192.168.10.8 is directly connected, Serial0/1 O 192.168.10.12 [110/1562] via 192.168.10.5, 01:24:32, Serial0/0 [110/1562] via 192.168.10.10, 01:24:32, Serial0/1 10.0.0.0/24 is subnetted, 1 subnets C 10.0.4.0 is directly connected, FastEthernet0/0 Everything looks fine here Check on RIP redistribution into OSPF Berlin#show ip protocols Routing Protocol is "ospf 1" Sending updates every 0 seconds Invalid after 0 seconds, hold down 0, flushed after 0 Outgoing update filter list for all interfaces is Incoming update filter list for all interfaces is Redistributing: ospf 1, rip Routing for Networks: 192.168.10.8/30 192.168.10.12/30 Routing Information Sources: Gateway Distance Last Update 192.168.72.1 110 00:03:48 192.168.10.9 110 00:03:48 Distance: (default is 110) Routing Protocol is "rip" Sending updates every 30 seconds, next due in 16 seconds Invalid after 180 seconds, hold down 180, flushed after 240 Outgoing update filter list for all interfaces is Incoming update filter list for all interfaces is Redistributing: rip Default version control: send version 2, receive version 2 Interface Send Recv Triggered RIP Key-chain Interface Send Recv Triggered RIP Key-chain FastEthernet0/0 2 2

Loopback0 2 2

Loopback1 2 2

Loopback10 2 2

Routing for Networks:

10.0.0.0

Routing Information Sources:

Gateway Distance Last Update

Distance: (default is 120)

Frankfurt#show ip protocols

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Routing Protocol is "ospf 1"

Sending updates every 0 seconds

Invalid after 0 seconds, hold down 0, flushed after 0

Outgoing update filter list for all interfaces is

Incoming update filter list for all interfaces is

Redistributing: ospf 1, rip

192.168.10.4/30

192.168.10.8/30

10.0.3.1 110 00:03:03

192.168.72.1 110 00:03:03

Routing Protocol is "rip"

Sending updates every 30 seconds, next due in 15 seconds

Invalid after 180 seconds, hold down 180, flushed after 240

Outgoing update filter list for all interfaces is

Incoming update filter list for all interfaces is

Redistributing: rip

Default version control: send version 2, receive version 2

Interface Send Recv Triggered RIP Key-chain

FastEthernet0/0 2 2

10.0.0.0

Next, examine the ospf database

Frankfurt#show ip ospf database

OSPF Router with ID (192.168.10.9) (Process ID 1)

Router Link States (Area 0)

Link ID ADV Router Age Seq# Checksum Link count

10.0.3.1 10.0.3.1 67 0x8000000A 0x80FC 4

192.168.10.9 192.168.10.9 752 0x80000017 0x1FF2 4

192.168.72.1 192.168.72.1 95 0x8000000A 0xBB64 5

Frankfurt#show ip ospf database

OSPF Router with ID (192.168.10.9) (Process ID 1)

Router Link States (Area 0)

Link ID ADV Router Age Seq# Checksum Link count

10.0.3.1 10.0.3.1 67 0x8000000A 0x80FC 4

192.168.10.9 192.168.10.9 752 0x80000017 0x1FF2 4

192.168.72.1 192.168.72.1 95 0x8000000A 0xBB64 5

Notice that none of the remote RIP networks are populating the OSPF data-bases

The “subnets” keyword tells OSPF to redistribute all subnet routes Without the subnets keyword, only networks that are not subnetted will be redistributed by OSPF; that is why none of the RIP networks are being properly redistributed Issue the following commands on Berlin and Frankfurt to resolve this issue

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Berlin(config)#router ospf 1

Berlin(config-router)#redistribute rip subnets

Frankfurt(config)#router ospf 1

Frankfurt(config-router)#redistribute rip subnets

Step 6

What were the results of your implementation? Did it fix the problem? List your results and observations below

Check the routing tables for the appropriate RIP routes

Berlin#show ip route

O 192.168.72.0/24 [110/782] via 192.168.10.14, 00:00:13, Serial0/0

O 192.168.10.4 [110/1562] via 192.168.10.14, 00:00:13, Serial0/0

[110/1562] via 192.168.10.9, 00:00:13, Serial0/1

O E2 10.0.4.0 [110/20] via 192.168.10.9, 00:00:14, Serial0/1

Frankfurt#show ip route

O 192.168.72.0/24 [110/782] via 192.168.10.5, 00:01:23, Serial0/0

O 192.168.10.12 [110/1562] via 192.168.10.5, 00:01:23, Serial0/0

[110/1562] via 192.168.10.10, 00:01:23, Serial0/1

O E2 10.0.2.0 [110/20] via 192.168.10.10, 00:01:23, Serial0/1

O E2 10.0.3.0 [110/20] via 192.168.10.10, 00:01:23, Serial0/1

O E2 10.0.1.0 [110/20] via 192.168.10.10, 00:01:23, Serial0/1

Westasman#show ip route

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C 192.168.72.0/24 is directly connected, FastEthernet0/0

O 192.168.10.8 [110/1562] via 192.168.10.6, 00:27:18, Serial0/1

[110/1562] via 192.168.10.13, 00:27:18, Serial0/0

O E2 10.0.2.0 [110/20] via 192.168.10.13, 00:08:08, Serial0/0

O E2 10.0.3.0 [110/20] via 192.168.10.13, 00:08:08, Serial0/0

O E2 10.0.1.0 [110/20] via 192.168.10.13, 00:08:08, Serial0/0

O E2 10.0.4.0 [110/20] via 192.168.10.6, 00:01:55, Serial0/1

Perform extended pings to verify the routing table entries

Westasman#ping

Protocol [ip]:

Target IP address: 10.0.4.1

Repeat count [5]:

Datagram size [100]:

Timeout in seconds [2]:

Extended commands [n]: y

Source address or interface: 192.168.72.1

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]:

!!!!!

Westasman#ping

Protocol [ip]:

Target IP address: 10.0.1.1

Repeat count [5]:

Datagram size [100]:

Timeout in seconds [2]:

Extended commands [n]: y

Source address or interface: 192.168.72.1

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]:

!!!!!

Step 7

If your solution did not fix the problem, repeat the process again If your solution did fix the problem, document your fix below

Added the keyword “subnets” to the redistribute command within the OSPF 1 process This command properly redistributed the 10.x.x.x networks into OSPF

Tiêu đề	Ospf Troubleshooting
Trường học	Cisco Networking Academy
Chuyên ngành	Internetwork Troubleshooting
Thể loại	Bài tập lab
Năm xuất bản	2001
Thành phố	Berlin

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