ospf: how bird select best route

10 Jul 2014

      Hello,

I advertise default gateway 0/0 from 2 juniper routers into servers with 
bird. On one router (.14) advertise with  metric 30 on second router 
(.9) with metric 70. I see  LSA from both routers but bird always select 
metric 70 as better.. Beside metrics rest configuration are identical..

bird> show  route 0.0.0.0/0
0.0.0.0/0          via 1.1.1.9 on bond0 [MyOSPF 00:11:12] * E2 
(150/10/70) [1.1.1.9]

when i turn off router with higher metric:
bird> show  route 0.0.0.0/0
0.0.0.0/0          via 1.1.1.14 on bond0 [MyOSPF 00:39:45] * E2 
(150/10/30) [1.1.1.14]

and when i turn on again router, bird choose metric 70 as better:

bird> show  route 0.0.0.0/0
0.0.0.0/0          via 1.1.1.9 on bond0 [MyOSPF 00:40:55] * E2 
(150/10/70) [1.1.1.9]

bird> show ospf neighbors
MyOSPF:
Router ID       Pri          State      DTime   Interface  Router IP
1.1.1.14  128         full/other  00:40   bond0      1.1.1.14
1.1.1.9  128         full/dr     00:38   bond0      1.1.1.9

bird> show ospf lsadb
Global
  Type   LS ID           Router           Age  Sequence  Checksum
  0005  0.0.0.0         11.1.1.9   1395  800000bc    ce57
  0005  0.0.0.0         11.1.1.14   1698  800000c0    52a6

protocol ospf MyOSPF {
         tick 2;
#       debug { states, routes, interfaces };
         import filter ospf_import;
         export filter ospf_export;
         rfc1583compat yes;
         area 112 {
                 interface "bond0" {
                         authentication none;
                         hello 10;
                         poll 30;
                         type nonbroadcast;
                         neighbors { 1.1.1.9 eligible;
                                     1.1.1.14 eligible;
};
         };
};

};

thanks for help,
Peter

ospf: how bird select best route

Piotr