bgp question

[Abhi]

Two router which are connected via switch are in HSRP mode , i.e one is actove at a time , the servers which are behind the switch have HSRP ip as gateway , now i have two links one is primary and other is secondary link coneected to the two routers . My requirement is when primary links fails then the seondary link would be able to forward the traffic . Issue is i cannot shift the HSRP as more other customers are connted to same router and traffic would always come to this router which is connected to primary link ( down currently ) . now i want router 1 should forward traffic to router 2 via IBGP so i want to know apart from defining two routers with same AS number as BGP neighbour what else is required ? should i use command next-hop-self and where to use and i cant run any dynamic routing protocol like OSPF etc . i can write static routes .

[Richard Burts]

There are some aspects of your question that I do not understand. For example, if the primary link has gone down, why would you not want HSRP to shift so that the router with the active link becomes the active HSRP router? I also do not understand why it is ok to run BGP but is not ok to run an interior protocol like OSPF, or EIGRP, or even RIP?

But you asked a question about configuring IBGP and there are answers to that. The most important requirement is that both routers specify the same AS number. Beyond that most things are optional. If the routers are directly connected (as they would be for HSRP) and if you use the addresses of that link as the neighbor address then there is no need to configure next hop self.

For this solution to be effective the routers at the other end of the links need to run EBGP to your routers and need to advertise at least a defult route to you. In this case you probably want to configure local preference on your routers so that the default route learned on the primary circuit will be preferred.

HTH

Rick

[milan.kulik]

Hi,

do I understand correctly each of your routers has an eBGP session to your backbone or Internet provider over the link connected to him?

In that case, yes, the iBGP  solution is the easiest one.

Just apply

neighbor your-second-router next-hop-self

command within your configuration.

Without that, you would need a static route to the provider router peering with your second router.

As Richard noticed, it should be possible to track your line status and let  the HSRP active router change in i case the line goes down.

But IMHO, this would not work in a case the line is Up but the eBGP peering to your provider went down for any reason.

(And you said you want to keep the HSRP active router on your primary one as long as it's alive anyway, correct?)

HTH,

Milan