R1 (Working ospf Int to R2) interface FastEthernet3/0 description P_T_P_to_R2 ip address xxx.xxx.66.1 255.255.255.252 ip route-cache flow ip ospf message-digest-key 10 md5 xx ip ospf cost 100 duplex full mpls ip mpls mtu 1530 R1 ("Not" Working ospf Int to R2) interface Port-channel1.87 description P_T_P_to_R2 encapsulation dot1Q 87 ip address xxx.xxx.66.61 255.255.255.252 ip ospf message-digest-key 10 md5 xx ip ospf cost 190 no snmp trap link-status mpls ip mpls mtu 1530 R2 (Working ospf Int to R1) interface Port-channel1.86 description P_T_P_to_R1 encapsulation dot1Q 86 ip address xxx.xxx.66.2 255.255.255.252 ip mtu 1500 ip ospf message-digest-key 10 md5 xx ip ospf cost 100 mpls mtu 1530 mpls ip R2 ("Not" Working ospf Int to R1) interface Port-channel1.87 description P_T_P_to_R1 encapsulation dot1Q 87 ip address xxx.xxx.66.62 255.255.255.252 ip mtu 1500 ip ospf message-digest-key 10 md5 xx ip ospf cost 190 mpls mtu 1530 mpls ip With both adj. up(From R1): Neighbor ID Pri State Dead Time Address Interface xxx.xxx.76.248 1 FULL/DR 00:00:00 xxx.xxx.66.62 Port-channel1.87 xxx.xxx.76.248 1 FULL/DR 00:00:39 xxx.xxx.66.2 FastEthernet3/0 Then "new" link loses adj. after ~60seconds Neighbor ID Pri State Dead Time Address Interface xxx.xxx.76.248 1 FULL/DR 00:00:38 xxx.xxx.66.2 FastEthernet3/0 Then both adj. back up Neighbor ID Pri State Dead Time Address Interface xxx.xxx.76.248 1 FULL/DR 00:00:37 xxx.xxx.66.62 Port-channel1.87 xxx.xxx.76.248 1 FULL/DR 00:00:37 xxx.xxx.66.2 FastEthernet3/0 R1 logs Nov 12 10:12:48.716 aest: OSPF: xxx.xxx.76.248 address xxx.xxx.66.62 on Port-channel1.87 is dead Nov 12 10:12:48.716 aest: OSPF: xxx.xxx.76.248 address xxx.xxx.66.62 on Port-channel1.87 is dead, state DOWN Nov 12 10:12:48.716 aest: %OSPF-5-ADJCHG: Process 100, Nbr xxx.xxx.76.248 on Port-channel1.87 from FULL to DOWN, Neighbor Down: Dead timer expired Nov 12 10:12:48.716 aest: OSPF: Neighbor change Event on interface Port-channel1.87 Nov 12 10:12:48.716 aest: OSPF: DR/BDR election on Port-channel1.87 Nov 12 10:12:48.716 aest: OSPF: Elect BDR xxx.xxx.76.238 Nov 12 10:12:48.716 aest: OSPF: Elect DR xxx.xxx.76.238 Nov 12 10:12:48.716 aest: OSPF: Elect BDR 0.0.0.0 Nov 12 10:12:48.716 aest: OSPF: Elect DR xxx.xxx.76.238 Nov 12 10:12:48.716 aest: DR: xxx.xxx.76.238 (Id) BDR: none Nov 12 10:12:48.716 aest: OSPF: Reset Port-channel1.87 flush timer Nov 12 10:12:48.716 aest: OSPF: Remember old DR xxx.xxx.76.248 (id) Nov 12 10:12:49.216 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:49.216 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:49.216 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:49.216 aest: OSPF: Build router LSA for area 0.0.0.0, router ID xxx.xxx.76.238, seq 0x80014360, process 100 Nov 12 10:12:49.216 aest: OSPF: No full nbrs to build Net Lsa for interface Port-channel1.87 Nov 12 10:12:51.716 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:51.732 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.432 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.432 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.432 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.432 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.448 aest: OSPF: 2 Way Communication to xxx.xxx.76.248 on Port-channel1.87, state 2WAY Nov 12 10:12:58.448 aest: OSPF: Neighbor change Event on interface Port-channel1.87 Nov 12 10:12:58.448 aest: OSPF: DR/BDR election on Port-channel1.87 Nov 12 10:12:58.448 aest: OSPF: Elect BDR 0.0.0.0 Nov 12 10:12:58.448 aest: OSPF: Elect DR xxx.xxx.76.248 Nov 12 10:12:58.448 aest: OSPF: Elect BDR xxx.xxx.76.238 Nov 12 10:12:58.448 aest: OSPF: Elect DR xxx.xxx.76.248 Nov 12 10:12:58.448 aest: DR: xxx.xxx.76.248 (Id) BDR: xxx.xxx.76.238 (Id) Nov 12 10:12:58.448 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0x1717 opt 0x52 flag 0x7 len 32 Nov 12 10:12:58.448 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.448 aest: OSPF: Set Port-channel1.87 flush timer Nov 12 10:12:58.448 aest: OSPF: Remember old DR xxx.xxx.76.238 (id) Nov 12 10:12:58.448 aest: OSPF: Neighbor change Event on interface Port-channel1.87 Nov 12 10:12:58.448 aest: OSPF: DR/BDR election on Port-channel1.87 Nov 12 10:12:58.448 aest: OSPF: Elect BDR xxx.xxx.76.238 Nov 12 10:12:58.448 aest: OSPF: Elect DR xxx.xxx.76.248 Nov 12 10:12:58.448 aest: DR: xxx.xxx.76.248 (Id) BDR: xxx.xxx.76.238 (Id) Nov 12 10:12:58.464 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB50 opt 0x52 flag 0x7 len 32 mtu 1500 state EXSTART Nov 12 10:12:58.464 aest: OSPF: NBR Negotiation Done. We are the SLAVE Nov 12 10:12:58.464 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB50 opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.464 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.484 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB51 opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.484 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB51 opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.484 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.500 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB52 opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.500 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB52 opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.500 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.520 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB53 opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.520 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB53 opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.520 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.536 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB54 opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.536 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB54 opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.536 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.552 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB55 opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.552 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB55 opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.552 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.572 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB56 opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.572 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB56 opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.572 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.588 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB57 opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.588 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB57 opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.588 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.604 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB58 opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.604 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB58 opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.604 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.624 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB59 opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.624 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB59 opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.624 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.640 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB5A opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.640 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB5A opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.640 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.656 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB5B opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.656 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB5B opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.656 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.676 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB5C opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.676 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB5C opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.676 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.692 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB5D opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.692 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB5D opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.692 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.708 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB5E opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.708 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB5E opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.708 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.728 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB5F opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.728 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB5F opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.728 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.744 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB60 opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.744 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB60 opt 0x52 flag 0x2 len 1412 Nov 12 10:12:58.744 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.760 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB61 opt 0x52 flag 0x3 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.760 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB61 opt 0x52 flag 0x2 len 92 Nov 12 10:12:58.760 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.776 aest: OSPF: Rcv DBD from xxx.xxx.76.248 on Port-channel1.87 seq 0xB62 opt 0x52 flag 0x1 len 92 mtu 1500 state EXCHANGE Nov 12 10:12:58.776 aest: OSPF: Exchange Done with xxx.xxx.76.248 on Port-channel1.87 Nov 12 10:12:58.776 aest: OSPF: Synchronized with xxx.xxx.76.248 on Port-channel1.87, state FULL Nov 12 10:12:58.776 aest: %OSPF-5-ADJCHG: Process 100, Nbr xxx.xxx.76.248 on Port-channel1.87 from LOADING to FULL, Loading Done Nov 12 10:12:58.776 aest: OSPF: Send DBD to xxx.xxx.76.248 on Port-channel1.87 seq 0xB62 opt 0x52 flag 0x0 len 32 Nov 12 10:12:58.780 aest: OSPF: Send with youngest Key 10 Nov 12 10:12:58.948 aest: OSPF: Reset old DR on Port-channel1.87 R2 logs: Nov 12 10:12:58.436 AEST: OSPF: Cannot see ourself in hello from xxx.xxx.76.238 on Port-channel1.87, state INIT Nov 12 10:12:58.436 AEST: OSPF: Neighbor change Event on interface Port-channel1.87 Nov 12 10:12:58.436 AEST: OSPF: DR/BDR election on Port-channel1.87 Nov 12 10:12:58.436 AEST: OSPF: Elect BDR 0.0.0.0 Nov 12 10:12:58.436 AEST: OSPF: Elect DR xxx.xxx.76.248 Nov 12 10:12:58.436 AEST: DR: xxx.xxx.76.248 (Id) BDR: none Nov 12 10:12:58.436 AEST: OSPF: Send with youngest Key 10 Nov 12 10:12:58.452 AEST: OSPF: Rcv DBD from xxx.xxx.76.238 on Port-channel1.87 seq 0x1717 opt 0x52 flag 0x7 len 32 mtu 1500 state INIT Nov 12 10:12:58.452 AEST: OSPF: 2 Way Communication to xxx.xxx.76.238 on Port-channel1.87, state 2WAY Nov 12 10:12:58.452 AEST: OSPF: Neighbor change Event on interface Port-channel1.87 Nov 12 10:12:58.452 AEST: OSPF: DR/BDR election on Port-channel1.87 Nov 12 10:12:58.452 AEST: OSPF: Elect BDR xxx.xxx.76.238 Nov 12 10:12:58.452 AEST: OSPF: Elect DR xxx.xxx.76.248 Nov 12 10:12:58.452 AEST: DR: xxx.xxx.76.248 (Id) BDR: xxx.xxx.76.238 (Id) Nov 12 10:12:58.452 AEST: OSPF: Port-channel1.87 Nbr xxx.xxx.76.238: Prepare dbase exchange Nov 12 10:12:58.452 AEST: OSPF: Send DBD to xxx.xxx.76.238 on Port-channel1.87 seq 0xB50 opt 0x52 flag 0x7 len 32 Nov 12 10:12:58.452 AEST: OSPF: Send with youngest Key 10 Nov 12 10:12:58.452 AEST: OSPF: First DBD and we are not SLAVE Nov 12 10:12:58.472 AEST: OSPF: Rcv DBD from xxx.xxx.76.238 on Port-channel1.87 seq 0xB50 opt 0x52 flag 0x2 len 1412 mtu 1500 state EXSTART Nov 12 10:12:58.472 AEST: OSPF: NBR Negotiation Done. We are the MASTER Nov 12 10:12:58.472 AEST: OSPF: Port-channel1.87 Nbr xxx.xxx.76.238: Summary list built, size 1176 Nov 12 10:12:58.472 AEST: OSPF: Send DBD to xxx.xxx.76.238 on Port-channel1.87 seq 0xB51 opt 0x52 flag 0x3 len 1412 Nov 12 10:12:58.472 AEST: OSPF: Send with youngest Key 10 Nov 12 10:12:58.488 AEST: OSPF: Rcv DBD from xxx.xxx.76.238 on Port-channel1.87 seq 0xB51 opt 0x52 flag 0x2 len 1412 mtu 1500 state EXCHANGE Nov 12 10:12:58.488 AEST: OSPF: Send DBD to xxx.xxx.76.238 on Port-channel1.87 seq 0xB52 opt 0x52 flag 0x3 len 1412 Cheers