05-01-2018 08:51 AM - edited 03-05-2019 10:22 AM
If I execute the command "show ip bgp neighbor x.x.x.x received-routes" and the router is learning a particular route via another routing protocol with a lower cost as well, will that route be omitted from the output of that command?
For example, I am learning a route via OSPF from one neighbor and iBGP from another neighbor. Ospf wins due to AD and so the OSPF route is injected into the local routing table. If I execute the command show ip bgp neighbor x.x.x.x received-routes (where I specify the iBGP neighbor by IP) shouldn't I see that route as a received route from the iBGP neighbor regardless of what route is in my routing table?
Thanks!
05-01-2018 08:58 AM - edited 05-01-2018 09:02 AM
Yes, prefix should appear in the bgp rib. But make sure that ibgp neighbor is advertising the prefix in question, bgp speaking router will only advertise best routes/prefixes and also keep in mind that iBGP neighbors don't advertise prefix that they learned from another ibgp neighbor to another iBGP neighbor/s, to overcome this issue you can either configure route reflectors or confederation.
You can run following command to make sure if the neighbor is advertising the prefix through bgp:
sh ip bgp neighbor x.x.x.x advertised-routes
05-01-2018 09:14 AM
Thanks Cofee
Unfortunately, I don't have access to that router, its a Verizon core router. I can see that it is being advertised into BGP from the edge where the network lives, but don't see it from another location coming from the core using that command. I do see it coming from another neighbor via OSPF via backup circuit.
When we suppressed the route via prefix list in OSPF configuration, it populated the routing table from BGP.
I just thought I should have seen the prefix in bgp received-routes.
05-01-2018 09:34 AM
Whether you suppress or unsuppress it via ospf, the prefix should be there if it's being advertised to you.
Please run "sh ip bgp" and see if the prefix is present in the bgp rib.
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