I have a Cisco Router as OSPF neighbor of a Nortel ERS 8600(point-to-point), we have changed the Hello and Retransmission Interval to 1 and 4 respectively; the adjacency is in FULL state, but OSPF is not learning any routing in either side, even tough they are receiving LSA on both sides.
Have anyone had a similar scenario?
Thanks in advance...
I have face similar issue between two cisco routers and resolved by below two interface command
ip ospf network point-to-point
ip mtu 1500
hope useful to you
In the ICND2 book I've found these potential problems:
- subnet mask used on the subnet
- subnet number
- hello interval
- dead interval
- OSPF area ID
- value of the stub area flag
Let's not jump to conclusions. There are insufficient information to suggest any particular solution. Mahesh, your idea is very good and it is indeed possible that there is a network type mismatch but let's not modify the network type just yet.
Is it possible to to paste the output of show ip ospf database and show ip ospf database router on the Cisco here? Also, what is the network type identified on the interconnection between the Cisco and the Nortel? Is some of these interfaces configured using IP Unnumbered?
If both devices are in the FULL state and they have successfully exchanged LSAs it means that there is basically a discrepancy in the topological databases. As Mahesh suggested, the most probable cause for this is the OSPF network type mismatch but it would be fine to verify that beforehand. What is the link technology used to interconnect the Cisco and Nortel, anyway?
Thanks guys, the routers now have routes populated by OSPF. The problem was the network type on the Nortel side(not my side ); I request that they configure the type like "point to point" and the Nortel's people said they did. Today I sneak into the Nortel router and realized that theres no point to point network type so I change the Cisco to broadcast.
8600:5/config/ip# ospf interface 172.28.134.201 interface-type ?
type of the interface
Anyway I post the commands referent to OSPF when we had the issue, if someona can tell me from that output that the issue was the network type would be great for future troubleshooting.
CISCO-RTR>sh ip ospf 2 database
OSPF Router with ID (172.31.128.133) (Process ID 2)
Router Link States (Area 0.0.0.1)
Link ID ADV Router Age Seq# Checksum Link count
172.28.134.232 172.28.134.232 706 0x800004E2 0x0008BE 16
172.28.134.233 172.28.134.233 307 0x80000210 0x00B7EF 16
172.31.128.133 172.31.128.133 1758 0x8000004C 0x0037AF 3
Net Link States (Area 0.0.0.1)
Link ID ADV Router Age Seq# Checksum
172.28.134.194 172.28.134.233 304 0x80000050 0x00F15E
172.28.134.211 172.28.134.233 304 0x80000050 0x00FE4C
CISCO-RTR>sh ip ospf 2 neighbor
Neighbor ID Pri State Dead Time Address Interface
172.28.134.232 0 FULL/ - 00:00:03 172.28.134.201 GigabitEthernet0/3
CISCO-RTR>sh ip ospf 2 interface
Loopback1 is up, line protocol is up
Internet Address 172.31.128.133/32, Area 0.0.0.1
Process ID 2, Router ID 172.31.128.133, Network Type LOOPBACK, Cost: 1
Loopback interface is treated as a stub Host
GigabitEthernet0/3 is up, line protocol is up
Internet Address 172.28.134.202/30, Area 0.0.0.1
Process ID 2, Router ID 172.31.128.133, Network Type POINT_TO_POINT, Cost: 1
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 1, Dead 4, Wait 4, Retransmit 4
oob-resync timeout 40
Hello due in 00:00:00
Index 1/1, flood queue length 0
Last flood scan length is 37, maximum is 51
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 172.28.134.232
Suppress hello for 0 neighbor(s)
Unfortunately, this output does not contain the necessary information. Moreover, determining the cause from this output requires quite deep knowledge of OSPF operations. We would need to know the OSPF Router IDs of your Cisco and the Nortel, and then we would need to see the detailed output of two commands: show ip ospf database router adv-router X and show ip ospf database network adv-router X with the X being the RID of Cisco and Nortel (each command twice, total of 4 commands) to see the contents of the LSA-1 and LSA-2 generated by your two routers.
In this output, we could then identify a discrepancy:
If both routers were running on the same network type, either they would both indicate direct adjacency to each other (on point-to-point type), or both of them would indicate being adjacent to the network interconnecting them (on broadcast type).
It's quite late answer :), but I had similar issue and almost 100% sure that there was OSPF network-type mismatch. Nortel8600 was broadcast and cisco was point-to-point... There is no option to configure OSPF point-to-point type through regular way under OSPF configuration on Nortel8600 al least on version 188.8.131.52.
Just to help out others, I have had this issue too but due to a different reason.
What was happening is that one of the routers had 2 non-area0 interfaces but it was not connected to the backbone.