Say you have router A having routes with localpref 50, and router B with localpref 100. When A receives a prefix from B, it will be the best in A's table. Router A will not try to propagate routes with localpref 50, because only the best route are propagated (usually). And as the best route is that was received from B, then B will get nothing back.
I've a question to the list in regards to iBGP behaviour:
- the router in question imports all routes with a bgp_local_pref of 50 [A]
- the other routers import eBGP routes with a bgp_local_pref of 100 [B]
- my assumption would be that the lower preference route would
propagated via iBGP, however that is not the case
- the above router also receive the higher preference routes via iBGP
Is the default iBGP behaviour to *not* export routes with lower
preference to other routers? That would explain the behaviour I see.
Best regards,
Nico
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