Inject BGP routes with non directly-connected next-hop

[Jan Huňka]

Hello,

I'm currently trying to configure BIRD for BGP injection. Routes which are
added on BIRD should be distributed to specified neighbor router (in this
case Cisco) and added to it's routing table. I also need to specify
next-hop IP address of these routes, because injected routes should divert
the matching traffic through another way until BIRDS stops to distribute
these routes.

I was able to configure BIRD to inject these routes with specified next-hop
using internal BGP. But I also need it to work with external BGP. The
problem is that the next-hop IP of injected routes is a directly connected
network of the Cisco router and not BIRD's. BIRD doesn't know anything
about this network. So the question is, is it possible to inject routes
from BIRD to Cisco router using external BGP with next-hop IP address,
which is not directly connected to the BIRD router?

I should add that the BGP injection using external BGP works too, but only
If the next-hop IP is a directly connected network od the BIRD router.

Thank you for any advice.

Jan Huňka


Configuration of BIRD:

protocol device {
        scan time 10;
}

protocol static static_10 {
        route 5.100.100.0/24 reject;
}

# filters section (DO NOT REMOVE!)
filter filter_10 {
if ( proto = "static_10" ) then {
bgp_community.add((25511,444));
bgp_next_hop=3.100.100.1;
accept;
} else {
 reject;
}
}

protocol bgp bgp_10 {
local as 25511;
neighbor Y.Y.Y.Y as 25512;
import all;
export filter filter_10;
}

Configuration of the bgp process on the CISCO router:

router bgp 25512
 neighbor X.X.X.X remote-as 25511
!
address-family ipv4
  neighbor X.X.X.X activate
  no auto-summary
!
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