BGP NAT incoming route advertisement from neighboring router

Hi All,

I have a question can this be done with BGP

Our network connects to a number of different Mobile network operators, most of them now use cisco jasper. The problem we have is cisco jasper gives these Mobile network operators overlapping address ranges ( thanks cisco !! )
We are currently putting these over lapping ranges into there own vrf’s using fvrf and ivrf. This has work fine till lately when IPsec and BGP combined with fvrf and ivrf = they do not play well together (again thank you cisco jasper !! )
Which bring me to my question. Can i for example have one BGP neighbor advertise 10.1.1.0/24 and i change this route advertisement to for example 192.168.1.0/24. So if i use show ip bgp the 192.168.1.0/24 will show up in my route table. I know its a long shot but i thought i’d ask as i have solved all but this part of our problem.

Hi @shaunasromamad,

For this to work you would need to use an application layer BGP proxy that is able to modify the NLRI (routing information) in the BGP Update and Notification messages.

You can see how this might be achieved by using a software BGP stack like Quagga. The Quagga host then runs a script to modify the the NLRI according to some rules you define, and re-advertise it back into the network(s). Route control is sometimes implemented this way for “special” projects but it is not common.

Assuming the architecture can not change much in the short term, I think you are better off not taking a NAT design problem and involving routing. That is to say, use your routing tools, such as VRFs as you already are, and then direct traffic via a bi-directional NAT when interconnectivity is required.

In the longer term, you have several options, one of which is to take this opportunity to move to IPv6.

Kind regards,
Jon.