Try removing the "ip ospf mtu-ignore" from both ends -see if the adjacency comes up (past exchange). Try enabling debug to see what exactly is going on -you should see straight away what the crux of the problem is.
adam > -----Original Message----- > From: cisco-nsp <[email protected]> On Behalf Of Richard > Mikisa > Sent: Tuesday, July 9, 2019 4:58 PM > To: [email protected] > Subject: [c-nsp] OSPF flapping between Nexus 7000 and ASR 1001x > > Hi All, > > I am running OSPF across a point to point link between a Nexus 7000 and an > ASR1000x. > > The OSPF works fine but every couple of hours, it breaks and neighbor state > goes into EXCHANGE and remains there for another 40 minutes or so. It then > goes into full, OSPF comes up and all is well for another couple of hours or so > and then the cycle starts again. All the time, IP connectivity between the two > point to point IPs is up. > > Configuration as below.. > > ASR1001x#sh run int g0/0/1 > interface GigabitEthernet0/0/1 > description ** MPLS London - SO031732 ** mtu 9216 ip address > 10.32.250.17 255.255.255.252 ip ospf network point-to-point ip ospf mtu- > ignore negotiation auto cdp enable end > > ASR1000x#sh ip ospf neighbor > > Neighbor ID Pri State Dead Time Address Interface > 40.1.1.1 0 EXCHANGE/ - 00:00:33 10.32.250.18 > GigabitEtherne > t0/0/1 > 10.32.8.253 1 FULL/DR 00:00:32 10.32.250.1 > GigabitEtherne > t0/0/0 > > > On the Nexus > N7K1-LON-AGG# sh run int vlan 3960 > > interface Vlan3960 > no shutdown > mtu 9216 > ip address 10.32.250.18/30 > ip ospf cost 1 > ip ospf network point-to-point > no ip ospf passive-interface > ip ospf mtu-ignore > ip router ospf 100 area 0.0.0.32 > > N7K1-LON-AGG# sh ip ospf neighbors 10.32.250.2 OSPF Process ID 100 VRF > default Total number of neighbors: 15 > Neighbor ID Pri State Up Time Address Interface > 10.32.250.2 1 EXCHANGE/ - 00:05:06 10.32.250.17 Vlan3960 > N7K1-LON-AGG# > > And the logs on the ASR > > Jul 9 14:33:00.682: %OSPF-5-ADJCHG: Process 100, Nbr 40.1.1.1 on > GigabitEthernet0/0/1 from FULL to DOWN, Neighbor Down: Too many > retransmissions Jul 9 14:34:00.683: %OSPF-5-ADJCHG: Process 100, Nbr > 40.1.1.1 on > GigabitEthernet0/0/1 from DOWN to DOWN, Neighbor Down: Ignore timer > expired Jul 9 14:34:46.962: %CLNS-5-ADJCHANGE: ISIS (Overlay1): Adjacency > to N7K1-LON-OTV (Overlay1) Down, hold time expired Jul 9 14:39:56.543: > %OSPF-5-ADJCHG: Process 100, Nbr 40.1.1.1 on > GigabitEthernet0/0/1 from EXCHANGE to DOWN, Neighbor Down: Interface > down or detached Jul 9 14:55:20.865: %OSPF-5-ADJCHG: Process 100, Nbr > 40.1.1.1 on > GigabitEthernet0/0/1 from EXCHANGE to DOWN, Neighbor Down: Interface > down or detached .Jul 9 15:06:25.955: %OSPF-5-ADJCHG: Process 100, Nbr > 40.1.1.1 on > GigabitEthernet0/0/1 from EXCHANGE to DOWN, Neighbor Down: Too many > retransmissions .Jul 9 15:07:25.955: %OSPF-5-ADJCHG: Process 100, Nbr > 40.1.1.1 on > GigabitEthernet0/0/1 from DOWN to DOWN, Neighbor Down: Ignore timer > expired .Jul 9 15:37:57.514: %OSPF-5-ADJCHG: Process 100, Nbr 40.1.1.1 on > GigabitEthernet0/0/1 from LOADING to FULL, Loading Done .Jul 9 > 15:38:03.296: %CLNS-5-ADJCHANGE: ISIS (Overlay1): Adjacency to > 8478.AC22.FEC3 (Overlay1) Up, new adjacency .Jul 9 15:42:25.399: > %SEC_LOGIN-5-LOGIN_SUCCESS: Login Success [user: > richard.mikisa] [Source: 10.0.1.2] [localport: 22] at 15:42:25 UTC Tue Jul 9 2019 > > > Can someone advise on where to look? > -- > cheers > Richard > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
