How to troubleshoot and verifying ospf configuration
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OSPF configuration and operation can be verified and troubleshooted using several show commands: - The show ip route command displays all routes including OSPF internal routes. - The show ip ospf command displays OSPF process information like router ID, areas, and LSA timers. - The show ip ospf database command displays information on routers in the network like link IDs, ADV routers, and checksums. - The show ip ospf interface command displays interface OSPF settings like area, cost, DR/BDR election, and neighbors. - The show ip ospf neighbor command summarizes OSPF neighbor information and adjacency states. - The show ip protocols command
![How to Troubleshoot and Verifying OSPF Configuration?
There are several ways you can verify and troubleshoot OSPF configuration and
operation, listed below are the necessary command to do this:
How to verify OSPF Configuration:
Show IP route command
Show IP ospf command
Show ip ospf database command
Show ip ospf interface command
Show ipospfneighbour command
Show ip protocols command
Debugging ospf
The Show IP route command:
R1#sho ip route
10.0.0.0/30 is subnetted, 3 subnets
C 10.1.1.0 is directly connected, Serial0/0/1
O 10.10.10.0 [110/128] via 10.20.20.2, 00:05:14, Serial0/0/0
[110/128] via 10.1.1.2, 00:05:14, Serial0/0/1
C 10.20.20.0 is directly connected, Serial0/0/0
172.16.0.0/24 is subnetted, 1 subnets
O 172.16.10.0 [110/65] via 10.1.1.2, 00:05:14, Serial0/0/1
O 192.168.1.0/24 [110/65] via 10.20.20.2, 00:07:38, Serial0/0/0
C 192.168.20.0/24 is directly connected, FastEthernet0/0
R1#
Using the the above command displays all routes on the network, with the O
representing the OSPF internal routes. The Cs are directly connected networks. It also
found the dual route to the 10.10.10.0 network.
Using the show OSPF Command](https://image.slidesharecdn.com/howtotroubleshootandverifyingospfconfiguration-131011224820-phpapp01/85/How-to-troubleshoot-and-verifying-ospf-configuration-1-320.jpg)
How to troubleshoot and verifying ospf configuration
- 1. How to Troubleshoot and Verifying OSPF Configuration? There are several ways you can verify and troubleshoot OSPF configuration and operation, listed below are the necessary command to do this: How to verify OSPF Configuration: Show IP route command Show IP ospf command Show ip ospf database command Show ip ospf interface command Show ipospfneighbour command Show ip protocols command Debugging ospf The Show IP route command: R1#sho ip route 10.0.0.0/30 is subnetted, 3 subnets C 10.1.1.0 is directly connected, Serial0/0/1 O 10.10.10.0 [110/128] via 10.20.20.2, 00:05:14, Serial0/0/0 [110/128] via 10.1.1.2, 00:05:14, Serial0/0/1 C 10.20.20.0 is directly connected, Serial0/0/0 172.16.0.0/24 is subnetted, 1 subnets O 172.16.10.0 [110/65] via 10.1.1.2, 00:05:14, Serial0/0/1 O 192.168.1.0/24 [110/65] via 10.20.20.2, 00:07:38, Serial0/0/0 C 192.168.20.0/24 is directly connected, FastEthernet0/0 R1# Using the the above command displays all routes on the network, with the O representing the OSPF internal routes. The Cs are directly connected networks. It also found the dual route to the 10.10.10.0 network. Using the show OSPF Command
- 2. Another way of troubleshooting and verifying OSPF configuration is by using the Show IP ospf command; the following information will be displayed: R1#show ipospf Routing Process "ospf 1" with ID 192.168.20.1 Supports only single TOS(TOS0) routes Supports opaque LSA SPF schedule delay 5 secs, Hold time between two SPFs 10 secs Minimum LSA interval 5 secs. Minimum LSA arrival 1 secs Number of external LSA 0. Checksum Sum 0x000000 Number of opaque AS LSA 0. Checksum Sum 0x000000 Number of DCbitless external and opaque AS LSA 0 Number of DoNotAge external and opaque AS LSA 0 Number of areas in this router is 1. 1 normal 0 stub 0 nssa External flood list length 0 Area BACKBONE(0) Number of interfaces in this area is 3 Area has no authentication SPF algorithm executed 7 times Area ranges are Number of LSA 3. Checksum Sum 0x012733 Number of opaque link LSA 0. Checksum Sum 0x000000 Number of DCbitless LSA 0 Number of indication LSA 0 Number of DoNotAge LSA 0 Flood list length 0 R1# The above command displays OSPF information all ospf processes running on the router. Here you can find out the router ID, area information, SPF statistics and LSA timers information…
- 3. The Show IP OSPF Database Command Show ipospf database: This command can be used during network troubleshooting. R1#show ipospf database OSPF Router with ID (192.168.20.1) (Process ID 1) Router Link States (Area 0) Link ID ADV Router Age Seq# Checksum Link count 192.168.1.1 192.168.1.1 1321 0x80000005 0x0042ab 5 192.168.20.1 192.168.20.1 1281 0x80000005 0x00826a 5 172.16.10.1 172.16.10.1 1281 0x80000005 0x00621e 5 This command displays the information on the number of routers in the network or internetwork plus the neighboring routers ID. Here you can see three routers with their various IDs (which is the highest IP on each router). Also you can see the link ID. The ADV router is the advertising router. The checksum link count might display different numbers depending on the routing device. Show ipospf interface command explained. We use the following topology for demonstration.
- 4. The show ipospf interface command on R1, will display the following output: R1#show ipospf interface fa0/0 FastEthernet0/0 is up, line protocol is up Internet address is 192.168.20.1/24, Area 0 Process ID 1, Router ID 192.168.20.1, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 192.168.20.1, Interface address 192.168.20.1 No backup designated router on this network Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Hello due in 00:00:06 Index 1/1, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 1, maximum is 1 Last flood scan time is 0 msec, maximum is 0 msec Neighbor Count is 0, Adjacent neighbor count is 0 Suppress hello for 0 neighbor(s) Serial0/0/0 is up, line protocol is up Internet address is 10.20.20.1/30, Area 0 Process ID 1, Router ID 192.168.20.1, Network Type POINT-TO-POINT, Cost: 64 Transmit Delay is 1 sec, State POINT-TO-POINT, Priority 0 No designated router on this network No backup designated router on this network Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Hello due in 00:00:02 Index 2/2, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 1, maximum is 1 Last flood scan time is 0 msec, maximum is 0 msec Neighbor Count is 1 , Adjacent neighbor count is 1 Adjacent with neighbor 192.168.1.1 Suppress hello for 0 neighbor(s)
- 5. The above command displays the following information on each router interface: i. Area assignment ii. Interface IP address iii. Process ID iv. Router ID v. Network type vi. Cost vii. Priority viii. DR/BDR election information hello and dead timer intervals ix. Adjacent neighbour information The Show ipospfneighbour command: R1#show ipospf neighbor Neighbor ID Pri State Dead Time Address Interface 192.168.1.1 0 FULL/ - 00:00:33 10.20.20.2 Serial0/0/0 172.16.10.1 0 FULL/ - 00:00:32 10.1.1.2 Serial0/0/1 R1# The above command displays the summary of ospf information regarding and the adjacency state. This command is very useful on a production network. The Show IP protocols command: This command display the following information R1#show ip protocols Routing Protocol is "ospf 1" Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Router ID 192.168.20.1 Number of areas in this router is 1. 1 normal 0 stub 0 nssa Maximum path: 4 Routing for Networks: 192.168.20.0 0.0.0.255 area 0 10.20.20.0 0.0.0.3 area 0 10.1.1.0 0.0.0.3 area 0 Routing Information Sources: Gateway Distance Last Update 172.16.10.1 110 00:14:00 192.168.1.1 110 00:14:40 192.168.20.1 110 00:14:00 Distance: (default is 110) R1# This command is used to verify the type of protocols running on your router and network. The display above shows the OSPF process ID, OSPF router ID, type of OSPF area, networks and areas configured for OSPF neighboring router’s ID etc…etc.
- 6. The Debugging OSPF Command: Among information provided by this command is the : i. Debug ipospf packet: this command displays hello packets being sent and received on your router ii. Debugipospf hello: this command displays hello packets being sent and received on your router. It also displays more information than the debug ospf packet iii. The debug ipospfadj: shows DR and DBR elections on a broadcast and non-broadcast multi-access (NBMA) network. More Related Readings: How to Troubleshoot OSPF?