RE: eBGP, iBGP, injecting networks

I think the main concern you have here is the advertisement of the networks from two different ASN's to two different upstream providers. You'll have to set it up with your upstream ISP's to allow you to advertise all of the networks, but typically it's not a problem. You won't have an issue with routing loops as BGP speaker will drop a prefix that has its own ASN in the path-list. If you prepend properly to the AS path things will behave the way you want them to. This will provide your
inbound redundancy.


Colin Fowlie

greetings all,
wanted to send a mail and say thanks to all who responded on and off

there were a lot of great suggestions given.

for now, we achieved prefix announcement redundancy (i shouldn't
have called it router redundancy in the first post) in AS 1 by
duplicating our network statements in bgp and also our 'pull up',
static routes to Null0 254 in our routing table in another router in
AS1. It runs iBGP in ASN1 to our border router that talks to

we still need to achieve prefix announcement redundancy in ASN 2
tho. it looks like we are going to do this by putting network
statements and null0 254 routes into a router in ASN1. We only have
one router in ASN2, whereas we have 5 routers in ASN1.

this will lead to an inconsistent AS origin for the routes from ASN2
but that seems like the best, temp. workaround for now until we merge

thanks again.


Quoting Fowlie, Colin <>: