OSPF Problems

[jamesgreen3000]

Can anybody help me please.

I have two third party routers connected by fibre running OSPF between them.

Due to a new requirment i need to put one of these routers in a new location.

I cant reconfigure them which is a massive problem for me.

Is there any way i can make them think they are dirrectly connected across my EIGRP network so they will form there old OSPF NBR relationship.

[vvijaysa]

Hi James,

I think you have to redistribute all OSPF traffic into EIGRP network. Try using redistribute command. Apply this on a border router on which you have to run both OSPF and EIGRP and; redistribute EIGRP to OSPF network (also vice versa).

Thanks,

Vijay

[jamesgreen3000]

Sorry i should have been more clear i need to keep these two routers isolated from my EIGRP AS.

It does work if i redistribute but thats not the way my boss wants it.

[vvijaysa]

Hello James,

I guess the OSPF over GRE tunnel may solve your problem. However, it may have some setbacks at times of traffic congestion. Is it possible to share your existing and proposed network topology? Please let me know the devices (head/end) also.

Thanks,

Vijay

[almoncad]

Hello James,

I'm guessing that your EIGRP AS is between the two OSPF routers, so I think what you need to use is Frame Relay. Take a look at this link for more information about frame relay:

http://www.cisco.com/en/US/tech/tk713/tk237/technologies_tech_note09186a008014f8a7.shtml

http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a0080094054.shtml

[paolo bevilacqua]

Wrong forum, post in "WAN - IP routing". You can move your posting using the actions panel on the right.

[jamesgreen3000]

This is my network diagram. I hope this helps i am really stuck.

[Arun Seetha]

Hi,

This is must to form OSPF neighborship that both routers should be part of same IP subnet.

I would suggest you to check IRB (Integrated Routing abd Bridging configuration) of Cisco. This is like like extending LAN over WAN.

Try makeing the below mentioned changes.

1. At each site your OSPF routter and WAN router should be part of same LAN subnet. Currently switches are coming in between as L3 hop, which you hav eto avoid.

2. Configure IRB between two WAN routers

Your OSPF neighborshipshould come up.

[jamesgreen3000]

Could i use L2TP for this and if so how?

[Bilal Nawaz · Accepted solution]

Hello James, L2TPv3 seems like an OK work around to satisfy the requirement, it gives you flexibility in a way where you can have control of the placement of the routers, keeping the neighborships in up state after the move.

See here for a very easy guide: http://www.networkstudies.co.uk/2011/11/extend-your-lan-across-multiple-sites.html

You will have to dedicate one interface at each end through the transport network to hook these two up on the same LAN.

Hope this helps

Sent from Cisco Technical Support iPhone App

[jamesgreen3000]

Thanks a lot for this info.

The only problem is that we have a number of these horrible routes that we cant reconfigure but need separating. I think i may have caused myself a lot of work.