Hi, So I've seen this issue mentioned in past mailings, and the FAQ, but I think I might be experiencing a buggy form of it in Bird 1.3.10. In debug mode I'm getting this: May 23 23:59:06 wugpi bird: device1: Scanning interfaces May 23 23:59:06 wugpi bird: CTWUG: HELLO packet sent via eth0 May 23 23:59:06 wugpi bird: kernel1: Scanning routing table May 23 23:59:06 wugpi bird: kernel1: Pruning table master May 23 23:59:06 wugpi bird: kernel1: 172.18.102.32/32: reinstalling May 23 23:59:06 wugpi bird: Netlink: File exists May 23 23:59:06 wugpi bird: kernel1: 172.18.102.160/28: reinstalling May 23 23:59:06 wugpi bird: Netlink: File exists May 23 23:59:06 wugpi bird: kernel1: 172.18.102.224/28: reinstalling May 23 23:59:06 wugpi bird: Netlink: File exists May 23 23:59:06 wugpi bird: kernel1: 172.18.102.240/28: reinstalling May 23 23:59:06 wugpi bird: Netlink: File exists May 23 23:59:06 wugpi bird: kernel1: 172.18.128.0/22: reinstalling May 23 23:59:06 wugpi bird: Netlink: File exists May 23 23:59:06 wugpi bird: ... Those prefixes are from OSPF only, and are not alien routes. My routing table without bird: # ip route list default via 172.18.102.7 dev eth0 172.18.102.0/28 dev eth0 proto kernel scope link src 172.18.102.8 172.18.102.71 via 172.18.102.7 dev eth0 With bird: # ip route list default via 172.18.102.7 dev eth0 172.16.0.0/12 via 172.18.102.1 dev eth0 proto bird 172.18.0.0/16 via 172.18.102.1 dev eth0 proto bird 172.18.1.1 via 172.18.102.7 dev eth0 proto bird 172.18.100.0/24 via 172.18.102.1 dev eth0 proto bird 172.18.100.2 via 172.18.102.1 dev eth0 proto bird 172.18.100.16/30 via 172.18.102.1 dev eth0 proto bird 172.18.100.20/30 via 172.18.102.1 dev eth0 proto bird 172.18.100.22 via 172.18.102.1 dev eth0 proto bird 172.18.100.24/30 via 172.18.102.1 dev eth0 proto bird 172.18.100.28/30 via 172.18.102.1 dev eth0 proto bird 172.18.100.29 via 172.18.102.1 dev eth0 proto bird 172.18.101.0/24 via 172.18.102.1 dev eth0 proto bird 172.18.102.0/28 dev eth0 proto kernel scope link src 172.18.102.8 172.18.102.1 via 172.18.102.1 dev eth0 proto bird 172.18.102.16/29 via 172.18.102.1 dev eth0 proto bird 172.18.102.18 via 172.18.102.1 dev eth0 proto bird 172.18.102.24/30 via 172.18.102.1 dev eth0 proto bird 172.18.102.32 via 172.18.102.7 dev eth0 proto bird 172.18.102.64/28 via 172.18.102.7 dev eth0 proto bird 172.18.102.71 via 172.18.102.7 dev eth0 172.18.102.128/27 via 172.18.102.14 dev eth0 proto bird 172.18.102.160/28 via 172.18.102.11 dev eth0 proto bird 172.18.102.192/28 via 172.18.102.9 dev eth0 proto bird 172.18.102.208/28 via 172.18.102.12 dev eth0 proto bird 172.18.102.224/28 via 172.18.102.10 dev eth0 proto bird 172.18.102.240/28 via 172.18.102.13 dev eth0 proto bird 172.18.103.0/24 via 172.18.102.1 dev eth0 proto bird 172.18.103.1 via 172.18.102.1 dev eth0 proto bird 172.18.128.0/22 via 172.18.102.1 dev eth0 proto bird Kernel: # uname -a Linux wugpi 3.6.11+ #452 PREEMPT Fri May 17 14:25:40 BST 2013 armv6l GNU/Linux Bird config: filter ospfin { if net ~ 172.16.0.0/12 then accept; reject; } protocol kernel { learn; scan time 20; import none; export all; } protocol device { scan time 10; } protocol ospf CTWUG { import filter ospfin; export none; area 172.18.102.0 { interface "eth*" 172.16.0.0/12 { type broadcast; priority 0; }; }; } Any ideas please? Before I start fumbling in source code... :) Thanks, Aragon