BGP relation with same loopback IP on pri and backup router

Unanswered Question

Hey Guys,

My remote router has a BGP neighbor relation with the Loopback IP on my primary router. My backup router also has same loopback IP,but the loopback interface is shutdown. So if my primary goes down, my backup router will not form BGP relation with remote router and network goes down.

Will it cause a routing loop if I unshut the loopback interface on the backup router? Please suggest a solution


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Overall Rating: 5 (1 ratings)
Reza Sharifi Fri, 09/10/2010 - 18:22
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Hi Ram,

You should not assign the same loopack address to 2 different devices.  The loopck address should be unique per device. I suggest you change the backup router to a different loopback address and not the same as the primary



Hi Reza,

It is a design requirement, because the remote router (a proprietary box) can form only one neighbor relationship. Is there a way to make this design work and provide redundancy at the same time?

If the same setup was a physical interface, I can run HSRP and this will work fine. Problem is the loopback interface.



Lei Tian Sat, 09/11/2010 - 04:40
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Hi Ram,

Do you use that loopback for any other purpose? If not, then it should be fine. Just to make sure on the remote router, the primary route for ther loopback is pointing to the primary router, and when primary router fail it can dynamicly fail over to secondary.


Lei Tian


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