We've got a Cisco 7301 routers that forms OSPF adjacencies with an HA pair of 5020 firewalls. Recently I swapped this router out with a different router with the same IPs but different configs to test a new WAN connection. OSPF forms up just fine with the new router. After testing concluded and swapping back to the old router OSPF freaks out. The adjacencies get stuck in EXSTART. Cisco also says that this is an MTU mismatch condition, not true in my case. Failing the firewalls over did not clear this up, tried twice. Rebooting them did the trick. After the reboot and a failover the adjacency was just fine. Aug 11 00:15:14: %OSPF-5-ADJCHG: Process 200, Nbr 10.16.0.12 on GigabitEthernet0/0.200 from EXSTART to DOWN, Neighbor Down: Too many retransmissions Aug 11 00:16:04: %OSPF-5-ADJCHG: Process 200, Nbr 10.16.1.20 on GigabitEthernet0/0.200 from DOWN to DOWN, Neighbor Down: Ignore timer expired Aug 11 00:17:14: %OSPF-5-ADJCHG: Process 200, Nbr 10.16.0.12 on GigabitEthernet0/0.200 from EXSTART to DOWN, Neighbor Down: Too many retransmissions Wondering if anyone else has seen this type of issue, or at least has any suggestions on how to get the adjacency to form without having to reboot.
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