OSPF update not working

[mcardell]

Good Morning,

I got the following problem:

4 router connected all with multiple ethernet broadcast area 0 between each other. They are also and connected also on the wan to remote sites and they are announcing these network to the 4 routers (connected between each other via multiple LAN segment in area 0 - actually 2 of the routers are 4500 with L3 capabilities).

The output of sh ip ospf neighbour is showing that some of the router neighbours are 2WAY/DROTHER.

Every router has got some ospf subnets to be redistributed and this does not happen.

I wanted that all the routes in the ospf database were announced, but from my understanding the routes are announced only to the DR and BDR (and then redistributed).

In this scenario the routers that established a 2way/DROTHER are not exchanging routes between themself.

What I expect is that they are receiving the routes (also in area 0)from conversation with DR and BDR.

In reality not all the route in my ospf database are similar.

On one of the router some routes announced by DROTHER are missing.

I thought that for a broadcast domain there is no problem of routes redistribution due to the any to any connectivity. It does not seem so.

Any suggestion, link to web site, idea?

Thanks

Matteo

[Georg Pauwen]

Hello Matteo,

do all your non-DR/BDR routers have a full neighbor relationship with the same DR/BDR ? Are you using some sort of rotuing policy or redistribution ? Can you post the configuration of one of the ´problem´ DROTHER routers, as well as the output of that router´s ´show ip ospf database´ ?

Regards,

GP

[mcardell]

Hi G,

Thanks for your comments.

Cannot post the conf (too complicated).

All the non-DR/BDR routers had full neighbor relationship.

Below the show neighbors.

All the Fe/VLAN connections are in area 0. ATM area 1/2.

I am using SVI in the 4500. The routers are connected to one switch each. The switches are connected and trunked between them. Everyone is connected to subnet 10.10.64.0 (vlan 64). Only the switches are connected to vlan 101 and 119.My issue is that the routers do not get the advertisement for subnet 101 and 119.

remember that 64, 101 and 119 are all in area 0.

My main problem was that R2 see the 101 and 119, but R1 does not get these routes.

ANy idea?

Thanks for your help.

[olufemi.amao]

In a broadcast environment OSPF would only be in a full state with the DR. All other routers would have a two-way adjacency established. This is normal behavior for OSPF.

http://www.cisco.com/warp/public/104/11.html

femmy

[Harold Ritter]

Just as a precision, you should have a full adjacency with the BDR as well.

Hope this helps,

[mcardell]

Thanks,

My routers are fully adjacencies with the BDR and DR, but still some routes are not propagated.

[Kevin Dorrell]

I have the impression that there is something else going on that is interfering with the routes. In theory, OSPF does not propagate routes within an area, but propagates information about links. Every router in the area should have an identical link-state database.

When you do a show ip ospf database, do all the routers show the same thing for area 0, or is there one that is different? They should all show the same thing: a complete map of area 0.

Edit: I have just been looking at your database output from you previous posting, and I am confused. You have Sw02 as 10.10.64.10 as well as Sw01 - I presume this is a misprint and you actually mean 10.10.64.20. The other thing that confuses me is that Router 1 has 10.10.119.0 in area 1, and Router 2 has 10.10.119.0 in area 2, both as type-3 s. So there is something about your architecture that I have not grasped yet.

I think it would be useful to see the configs.

Kevin Dorrell

Luxembourg