OSPF neighbor can't come up on a DMVPN spoke.
It all started with this message. Tun0 interface has always been up and connectivity has been verified.
*Apr 17 15:26:13.312: %OSPF-5-ADJCHG: Process 302, Nbr100.10.0.1 on Tunnel0 from FULL to DOWN, Neighbor Down: Interface down or detached
debug ip ospf packet
*Apr 17 15:38:23.938: OSPF-302 PAK Tu0: Drop packet, OSPF shut down on interface
CE2#show ip ospf int tun0
Tunnel0 is up, line protocol is up
Internet Address 100.10.0.9/24, Area 51, Attached via Interface Enable
Process ID 302, Router 100.10.0.9, Network Type BROADCAST, Cost: 1000
Topology-MTID Cost Disabled Shutdown Topology Name
0 1000 no no Base
Enabled by interface config, including secondary ip addresses
Transmit Delay is 1 sec, State DOWN, Priority 0
No designated router on this network
No backup designated router on this network
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
I am unable to find anything about "Drop packet, OSPF shut down on interface". Known bug?