iBGP not showing in routing table.

[tadamson]

I have two routers connected to individual ISPs. Each running BGP to their respective ISP. I want to have my two routers to share the tables so that if ISP-A is the shortest route, then it will take that link. So I set up iBGP between my routers. I get established states between the routers, and if I do a show ip bgp, the bgp routes show up, but if I do a show ip route bgp, then nothing appears. How do I get the tables to show properly?

[Richard Burts]

There are a couple of things that frequently cause the symptom of routes in the BGP table but not in the routing table. First thing to consider is whether the next hop address is reachable. On each of the routers do a show ip bgp, select a route (or several routes) note what is the next hop address for that route, and see if you can ping that next hop address from the router. If you can not successfully ping the next hop that would be why the routes are not in the table.

Another factor to consider is the question of synchronization which is normally required by IBGP. You could try adding the no sync command under BGP and see if it fixes the problem.

HTH

Rick

[Harold Ritter]

Just as a precision, BGP doesn't check that the next hop is pingable but only that it is present in the RIB. BGP's check for reachability is limited to the control plane level.

A "show ip bgp " is usually the best way to find out why the specific prefix is not installed in the RIB.

Hope this helps,

[thisisshanky]

Try a

"no sync" on both routers and see if that helps.

If the routes do show in "show ip bgp" and it does not show in ip routing table, you might want to set the next hop to self on each router or include the next hop subnet as part of your routing protocol or even configure a static route to reach that next hop subnet.

router bgp 100

neighbor x.x.x.x remote-as 100

neighbor x.x.x.x next-hop-self

HTH