OSPF: incorrect path computation for v2.0.5+?

Upgraded from 2.0.4 to 2.0.7 and observed strange OSPF path computation. Re-tested against v2.0.5, same result. Any known issues in this area? Setup when observing issue; 5 nodes connected in a ring with PPP links (some redundant links). /----------------------------------------------------------------\ ,------------. ,------------. ,------------. ,------------. ,------------. |10.210.139.1| |10.210.139.2| |10.210.139.3| |10.210.139.4| |10.210.139.5| | |---| |---| |---| |---| | | |---| |---| | | | | | `------------' `------------' `------------' `------------' `------------' With 2.0.4 node 10.210.139.1 finds shortest path to 10.210.139.5 via directly connected interface. With 2.0.5+ the OSPF computation results via hop-by-hop thru 10.210.139.2. Result with 2.0.4 ----------------- node_1 ~ # birdc BIRD v2.0.4-16-g1528cec5 ready. bird> show ospf interface ospfv2_1 ospfv2_1: Interface p1-1-3-1-4 (peer 10.210.139.5) Type: ptp Area: 0.0.0.0 (0) State: PtP Priority: 0 Cost: 10 Hello timer: 10 Wait timer: 40 Dead timer: 40 Retransmit timer: 5 Interface p1-1-1-1-2 (peer 10.210.139.2) Type: ptp Area: 0.0.0.0 (0) State: PtP Priority: 0 Cost: 10 Hello timer: 10 Wait timer: 40 Dead timer: 40 Retransmit timer: 5 Interface p1-1-5-1-6 (peer 10.210.139.2) Type: ptp Area: 0.0.0.0 (0) State: PtP Priority: 0 Cost: 10 Hello timer: 10 Wait timer: 40 Dead timer: 40 Retransmit timer: 5 bird> show ospf topology ospfv2_1 area 0.0.0.0 router 0.0.139.1 distance 0 router 0.0.139.5 metric 10 router 0.0.139.2 metric 10 router 0.0.139.2 metric 10 router 0.0.139.2 distance 10 router 0.0.139.3 metric 10 router 0.0.139.3 metric 10 router 0.0.139.1 metric 10 router 0.0.139.1 metric 10 router 0.0.139.3 distance 20 router 0.0.139.4 metric 10 router 0.0.139.2 metric 10 router 0.0.139.2 metric 10 router 0.0.139.4 distance 20 router 0.0.139.3 metric 10 router 0.0.139.5 metric 10 router 0.0.139.5 distance 10 router 0.0.139.4 metric 10 router 0.0.139.1 metric 10 bird> show route table master4 Table master4: 0.0.0.0/0 unicast [static1 14:11:45.720] * (254) via 10.210.129.1 on eth1 10.210.139.2/32 unicast [direct1 14:15:57.283] * (255) dev p1-1-1-1-2 unicast [ospfv2_1 14:16:12.888] E1 (145/10) [0.0.139.2] via 10.210.139.2 on p1-1-1-1-2 unicast [direct1 14:16:01.143] (255) dev p1-1-5-1-6 10.210.139.5/32 unicast [direct1 14:18:20.315] * (255) dev p1-1-3-1-4 unicast [ospfv2_1 14:18:34.888] E1 (145/10) [0.0.139.5] via 10.210.139.5 on p1-1-3-1-4 10.210.139.1/32 unicast [direct1 14:11:37.896] * (255) dev lo 10.210.139.4/32 unicast [ospfv2_1 14:18:34.888] * E1 (145/20) [0.0.139.4] via 10.210.139.5 on p1-1-3-1-4 10.210.129.0/24 unicast [direct1 14:11:45.720] * (255) dev eth1 10.210.139.3/32 unicast [ospfv2_1 14:17:58.888] * E1 (145/20) [0.0.139.3] via 10.210.139.2 on p1-1-1-1-2 10.0.0.0/20 unicast [direct1 14:11:21.625] * (255) dev eth0 bird> show route Table master4: 0.0.0.0/0 unicast [static1 14:23:07.805] * (254) via 10.210.129.1 on eth1 10.210.139.2/32 unicast [direct1 14:23:07.763] * (255) dev p1-1-1-1-2 unicast [ospfv2_1 14:23:22.813] E1 (145/10) [0.0.139.2] via 10.210.139.2 on p1-1-1-1-2 10.210.139.5/32 unicast [direct1 14:23:08.613] * (255) dev p1-1-3-1-4 unicast [ospfv2_1 14:23:22.813] E1 (145/40) [0.0.139.5] via 10.210.139.2 on p1-1-1-1-2 10.210.139.1/32 unicast [direct1 14:23:02.820] * (255) dev lo 10.210.139.4/32 unicast [ospfv2_1 14:23:22.813] * E1 (145/30) [0.0.139.4] via 10.210.139.2 on p1-1-1-1-2 10.210.129.0/24 unicast [direct1 14:23:07.805] * (255) dev eth1 10.210.139.3/32 unicast [ospfv2_1 14:23:22.813] * E1 (145/20) [0.0.139.3] via 10.210.139.2 on p1-1-1-1-2 10.0.0.0/20 unicast [direct1 14:22:38.675] * (255) dev eth0 Result with 2.0.5 and 2.0.7 --------------------------- node_1 ~ # birdc BIRD v2.0.5-1-gd383d5ba ready. bird> show ospf interface ospfv2_1 ospfv2_1: Interface p1-1-1-1-2 (peer 10.210.139.2) Type: ptp Area: 0.0.0.0 (0) State: PtP Priority: 0 Cost: 10 Hello timer: 10 Wait timer: 40 Dead timer: 40 Retransmit timer: 5 Interface p1-1-5-1-6 (peer 10.210.139.2) Type: ptp Area: 0.0.0.0 (0) State: PtP Priority: 0 Cost: 10 Hello timer: 10 Wait timer: 40 Dead timer: 40 Retransmit timer: 5 Interface p1-1-3-1-4 (peer 10.210.139.5) Type: ptp Area: 0.0.0.0 (0) State: PtP Priority: 0 Cost: 10 Hello timer: 10 Wait timer: 40 Dead timer: 40 Retransmit timer: 5 bird> bird> show ospf topology ospfv2_1 area 0.0.0.0 router 0.0.139.1 distance 0 router 0.0.139.2 metric 10 router 0.0.139.2 metric 10 router 0.0.139.5 metric 10 router 0.0.139.2 distance 10 router 0.0.139.3 metric 10 router 0.0.139.3 metric 10 router 0.0.139.1 metric 10 router 0.0.139.1 metric 10 router 0.0.139.3 distance 20 router 0.0.139.4 metric 10 router 0.0.139.2 metric 10 router 0.0.139.2 metric 10 router 0.0.139.4 distance 30 router 0.0.139.3 metric 10 router 0.0.139.5 metric 10 router 0.0.139.5 distance 40 router 0.0.139.4 metric 10 router 0.0.139.1 metric 10 bird> bird> show route table master4 Table master4: 0.0.0.0/0 unicast [static1 14:41:12.689] * (254) via 10.210.129.1 on eth1 10.210.139.2/32 unicast [direct1 14:41:06.967] * (255) dev p1-1-1-1-2 unicast [ospfv2_1 14:41:22.924] E1 (145/10) [0.0.139.2] via 10.210.139.2 on p1-1-1-1-2 unicast [direct1 14:41:08.739] (255) dev p1-1-5-1-6 10.210.139.5/32 unicast [direct1 14:41:41.577] * (255) dev p1-1-3-1-4 unicast [ospfv2_1 14:41:22.924] E1 (145/40) [0.0.139.5] via 10.210.139.2 on p1-1-1-1-2 10.210.139.1/32 unicast [direct1 14:41:04.950] * (255) dev lo 10.210.139.4/32 unicast [ospfv2_1 14:41:22.924] E1 (145/30) [0.0.139.4] via 10.210.139.2 on p1-1-1-1-2 10.210.129.0/24 unicast [direct1 14:41:12.689] * (255) dev eth1 10.210.139.3/32 unicast [ospfv2_1 14:41:22.924] E1 (145/20) [0.0.139.3] via 10.210.139.2 on p1-1-1-1-2 10.0.0.0/20 unicast [direct1 14:40:48.586] * (255) dev eth0 bird> bird> show ospf neighbors ospfv2_1 ospfv2_1: Router ID Pri State DTime Interface Router IP 0.0.139.2 0 Full/PtP 38.373 p1-1-1-1-2 10.210.139.2 0.0.139.2 0 Full/PtP 30.144 p1-1-5-1-6 10.210.139.2 0.0.139.5 0 Full/PtP 32.983 p1-1-3-1-4 10.210.139.5 bird>