Symptoms:
- ESG advertises BGP routes to neighbor with next-hop as neighbor address, instead of local address when default originate is enabled on the neighboring router.
show_ip_bgp
> 0.0.0.0/0 3.3.3.3 1 100 60 64523 i
- eBGP neighborship between ESG and neighbor.
- Routes affected are the ones learnt from an iBGP peer after the iBGP connection is flapped. It can cause traffic loss since next-hop for routes is incorrect.
- In BGP advertised routes command, we can see next-hop for routes is the neighbor IP instead of local IP.
show ip bgp neighbors 3.3.3.3 advertised-routes
[..]
1.1.1.0/24 3.3.3.3 0 0 ?
2.2.2.0/24 3.3.3.3 0 0 ?
[..]
- If we check the routes on the neighbor, the next-hop will be incorrect.