OSPF route selection.

Hi Experts,

Please refer to the diag below:

R1 is learning the route 90.1.1.0/24 from 2 ABRs, ie, R3 and R8. Its preferring the route through R8 even though the cost is HIGH.

I wonder why this is happening.


R1#sh ip route 90.1.1.1
Routing entry for 90.1.1.0/24
  Known via "ospf 100", distance 110, metric 1002, type intra area
  Last update from 18.1.1.2 on FastEthernet0/0, 00:16:34 ago
  Routing Descriptor Blocks:
  * 18.1.1.2, from 9.9.9.9, 00:16:34 ago, via FastEthernet0/0
      Route metric is 1002, traffic share count is 1


R1#sh ip ospf database SUMMary | b 90.1.1.0
  Link State ID: 90.1.1.0 (summary Network Number)
  Advertising Router: 1.1.1.1
  LS Seq Number: 80000001
  Checksum: 0x6E8
  Length: 28
  Network Mask: /24
        TOS: 0  Metric: 1002

  LS age: 365
  Options: (No TOS-capability, DC, Upward)
  LS Type: Summary Links(Network)
  Link State ID: 90.1.1.0 (summary Network Number)
  Advertising Router: 3.3.3.3
  LS Seq Number: 80000004
  Checksum: 0x9935
  Length: 28
  Network Mask: /24
        TOS: 0  Metric: 3