Tài liệu OSPF Troubleshooting pptx

1-7 Semester 8 Internetwork Troubleshooting v1.0 - Lab 13.2.1.1 Copyright  2001, Cisco Systems, Inc.
Lab 13.2.1.1: OSPF Troubleshooting
F0/0 192.168.72.1/24
S0/1 192.168.10.5/30S0/0 192.168.10.14/30
S0/0 192.168.10.13/30 S0/1 192.168.10.6/30
Fa0/0 10.0.1.1/24 Fa0/0 10.0.4.1/24
Westasman
Berlin Frankfurt
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.

2-7 Semester 8 Internetwork Troubleshooting v1.0 - Lab 13.2.1.1 Copyright  2001, Cisco Systems, Inc.
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.
Westasman#ping 10.0.1.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.0.1.1, timeout is 2 seconds:

Success rate is 0 percent (0/5)

Ping the WAN interface of Frankfurt.
Westasman#ping 192.168.10.6

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.10.6, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 32/32/36 ms
Ping the LAN interface of Frankfurt.
Westasman#ping 10.0.4.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.4.1, timeout is 2 seconds:

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

3-7 Semester 8 Internetwork Troubleshooting v1.0 - Lab 13.2.1.1 Copyright  2001, Cisco Systems, Inc.
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
C 192.168.10.12 is directly connected, 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
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 192.168.10.14, 01:23:27, Serial0/0
192.168.10.0/30 is subnetted, 3 subnets
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 192.168.10.8 is directly connected, Serial0/1
C 192.168.10.12 is directly connected, Serial0/0
10.0.0.0/24 is subnetted, 4 subnets
C 10.0.2.0 is directly connected, Loopback0

4-7 Semester 8 Internetwork Troubleshooting v1.0 - Lab 13.2.1.1 Copyright  2001, Cisco Systems, Inc.
C 10.0.3.0 is directly connected, Loopback1
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

5-7 Semester 8 Internetwork Troubleshooting v1.0 - Lab 13.2.1.1 Copyright  2001, Cisco Systems, Inc.
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:
192.168.10.4/30
192.168.10.8/30
Routing Information Sources:
Gateway Distance Last Update
10.0.3.1 110 00:03:03
192.168.72.1 110 00:03:03
Distance: (default is 110)

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

Interface Send Recv Triggered RIP Key-chain
FastEthernet0/0 2 2
Routing for Networks:
10.0.0.0
Routing Information Sources:
Gateway Distance Last Update
Distance: (default is 120)

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.

6-7 Semester 8 Internetwork Troubleshooting v1.0 - Lab 13.2.1.1 Copyright  2001, Cisco Systems, Inc.
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
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 192.168.10.14, 00:00:13, Serial0/0
192.168.10.0/30 is subnetted, 3 subnets
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
C 192.168.10.8 is directly connected, Serial0/1
C 192.168.10.12 is directly connected, Serial0/0
10.0.0.0/24 is subnetted, 4 subnets
C 10.0.2.0 is directly connected, Loopback0
C 10.0.3.0 is directly connected, Loopback1
C 10.0.1.0 is directly connected, FastEthernet0/0
O E2 10.0.4.0 [110/20] via 192.168.10.9, 00:00:14, Serial0/1

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, 00:01:23, 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, 00:01:23, Serial0/0

[110/1562] via 192.168.10.10, 00:01:23, Serial0/1
10.0.0.0/24 is subnetted, 4 subnets
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
C 10.0.4.0 is directly connected, FastEthernet0/0

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

Gateway of last resort is not set

7-7 Semester 8 Internetwork Troubleshooting v1.0 - Lab 13.2.1.1 Copyright  2001, Cisco Systems, Inc.

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, 00:27:18, Serial0/1
[110/1562] via 192.168.10.13, 00:27:18, Serial0/0
C 192.168.10.12 is directly connected, Serial0/0
10.0.0.0/24 is subnetted, 4 subnets
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]:
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.4.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 40/44/60 ms

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]:
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 32/32/36 ms
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.