Hello, can yomeone please explain me the following behaviour: There's one eBGP session (b_dtag1) and one iBGP session with one of our RR Servers (b_rr1). The RR redistributes the blackhole prefixes learned from the Spamhouse BGP Feed (BGPf). The prefix 64.112.128.0/18 is supposed to be blackholed. These are the two routes learned from the two peers: bird> show route all 64.112.128.0/18 64.112.128.0/18 via X.X.X.X on eth0 [b_dtag1 Apr06] * (100) [AS3320i] Type: BGP unicast univ BGP.origin: IGP BGP.as_path: 3320 3491 25847 46879 BGP.next_hop: X.X.X.X BGP.local_pref: 100 blackhole [b_rr1 15:36 from Y.Y.Y.Y] (100/-) [AS65535i] Type: BGP unicast univ BGP.origin: IGP BGP.as_path: 65190 BGP.next_hop: 192.168.2.11 BGP.med: 0 BGP.local_pref: 40000 BGP.community: (65190,1000) (65535,65281) As you can see the (older) regular eBGP route is picked over the blackhole route: Based on the Route selection rules from http://bird.network.cz/?get_doc&f=bird-6.html#ss6.2 I expected that the first (Prefer route with the highest Local Preference attribute) and the second (Prefer route with the shortest AS path) rule would result in the blackhole route being picked. Best Regards Thomas Goldberg