Hello Ryan,
You did not share your own BGP configuration so it is difficult to understand your setup in closer detail. However, from what you wrote, I understand that there is a BGP route server in your network, and you are trying to peer your own router to it, and you are not receiving any routes from it.
My first question is whether you have configured your own router with the no bgp enforce-first-as command in your BGP process configuration. This command is required on clients of BGP route servers - this is because route servers do not change the AS_PATH and next-hop attributes (they are transparent in this sense), yet they exist in their own AS, so for your router, the received advertisements are treated as malformed because the first ASN in the AS_PATH is not the ASN of the route server. The no bgp enforce-first-as command deactivates this sanity check. More details here:
https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/configuration/15-mt/irg-15-mt-book/irg-route-server.pdf
If configuring this command in your BGP process does not help then I would like to ask you to share the following details:
- The full configuration of your BGP process, including any related route-maps, prefix lists, AS_PATH lists, ACLs, etc. - everything that relates to BGP in your configuration
- If possible, I would also like you to create a standard ACL that permits exactly the route you expect to receive from the BGP route server, and then run a BGP debug as follows:
debug ip bgp update <ACL_number> in
Then execute the clear ip bgp <route-server-IP> in command, capture the output of the debugs, deactivate them with undebug all, and share the debug outputs with us. The debugs will show if the route is truly being received, and if it is, why is it being dropped.
Thank you!
Best regards,
Peter
