BGP No Advertise Community with Route Reflector
In a BGP Route Reflector (RR) cluster, if a route contains the "no-advertise" community, it will not be advertised to any other BGP peer, whether an RR, an RR client or a non-client. To handle such scenarios, network administrators can use their own internal communities along with Route Maps to manipulate this default route advertisement behavior. The process involves the following steps:
- Remove the "no-advertise" community from the received routes.
- Assign a custom community to the routes.
- On outbound routes, match the internal community and reapply the "no-advertise" community if necessary.
This method allows for fine-grained control over route distribution within an autonomous system (AS), ensuring that routing loops or suboptimal routing are avoided by maintaining consistent configurations across the RR cluster.
Links
https://networklessons.com/bgp/bgp-route-reflector/