OSFP Full Adjacency without routes in OSPF DataBase

Unanswered Question
Oct 2nd, 2010

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 this problem too.
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Mahesh Gohil Sat, 10/02/2010 - 22:34

Hi ,

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



Jernej Vodopivec Sat, 10/02/2010 - 22:45

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

- authentication

- value of the stub area flag

Peter Paluch Sun, 10/03/2010 - 00:35


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?

Best regards,


bernatellez Sun, 10/03/2010 - 08:04

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 interface-type ?

type of the interface

Required parameters:

        = ospf interface type {broadcast|nbma|passive}

Command syntax:


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 ( (Process ID 2)

                Router Link States (Area

Link ID         ADV Router      Age         Seq#       Checksum Link count  706         0x800004E2 0x0008BE 16  307         0x80000210 0x00B7EF 16  1758        0x8000004C 0x0037AF 3

                Net Link States (Area

Link ID         ADV Router      Age         Seq#       Checksum  304         0x80000050 0x00F15E  304         0x80000050 0x00FE4C


CISCO-RTR>sh ip ospf 2 neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface    0   FULL/  -        00:00:03  GigabitEthernet0/3


CISCO-RTR>sh ip ospf 2 interface

Loopback1 is up, line protocol is up

  Internet Address, Area

  Process ID 2, Router ID, Network Type LOOPBACK, Cost: 1

  Loopback interface is treated as a stub Host

GigabitEthernet0/3 is up, line protocol is up

  Internet Address, Area

  Process ID 2, Router ID, 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

  Next 0x0(0)/0x0(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

  Suppress hello for 0 neighbor(s)


Peter Paluch Sun, 10/03/2010 - 08:17


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:

  • The router running on point-to-point network type would indicate direct adjacency from itself to the neighboring router, and the interconnecting network would be identified as another stub network entry
  • The router running on broadcast network type would indicate direct adjacency from itself to the broadcast transit network

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).

Best regards,


jimmysands73_2 Sun, 10/03/2010 - 20:41

Good stuff Paul....thanks to both of you for following up on your orginal post....

Egor Egorov Mon, 12/02/2013 - 04:46


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



Ricardo Ferreira Mon, 03/30/2015 - 04:27

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.


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