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Nexus 7000 OSPFv3 stuck in EXSTART when communicating with an ASR1001x (OSPFv2 completes without problems)

mdella000
Beginner
Beginner

I currently have a Nexus 7000 (n7000-s2-dk9.6.2.16.bin) that is trying to communicate with an ASR 1001-x (v03.16.07b.S).  Both IPv4 and IPv6 are configured on the two routers. OSPFv2 handshakes without issues whereas OSPFv3 gets stuck on the Nexus in the EXSTART state (constantly cycles back to INIT, etc).

 

 

ASR1001-x

interface TenGigabitEthernet0/0/0.116
 encapsulation dot1Q 116
 ip address xxx.xxx.88.211 255.255.255.240
 standby version 2
 standby 116 ip xxx.xxx.88.209
 standby 116 authentication md5 key-string xxxxxxxxxx
 ipv6 address FE80::116:102 link-local
 ipv6 address xxxx:xxxx:130:1::102/64
 ipv6 enable
 ospfv3 101 priority 25
 ospfv3 101 ipv6 area 0

router ospf 101
 log-adjacency-changes detail
 network xxx.xx.88.208 0.0.0.15 area 0
 network xxx.xxx.103.24 0.0.0.7 area 0
 network xxx.xxx.103.251 0.0.0.0 area 0

router ospfv3 101
 address-family ipv6 unicast
 log-adjacency-changes detail
 exit-address-family

 

NEXUS7000

interface Vlan116
 vrf member tower_net
 ip address xxx.xxx.88.219/28
 ipv6 address xxxx:xxxx:130:1::1eaf:101/64
 ipv6 link-local fe80::116:199
 ip ospf cost 10
 ip router ospf 101 area 0.0.0.0
 ospfv3 cost 10
 no ospfv3 passive-interface
 ipv6 router ospfv3 101 area 0.0.0.0
 no shutdown

router ospf 101
 vrf tower_net
 network xxx.xxx.88.208/28 area 0.0.0.0
 network xxx.xxx.100.0/24 area 0.0.0.0
 network xxx.xxx.103.252/32 area 0.0.0.0
 log-adjacency-changes detail

router ospfv3 101
 vrf tower_net
 log-adjacency-changes detail
 address-family ipv6 unicast

 

Looking at the states for both OSPFv2 and OSPFv3 on the nexus, we get:

core-sv7-nexus1# sho ip ospf neighbors vrf tower_net
OSPF Process ID 101 VRF tower_net
Total number of neighbors: 3
Neighbor ID Pri State Up Time Address Interface
xxx.xxx.20.10 1 FULL/DROTHER 22w0d xxx.xxx.88.218 Vlan116
xxx.xxx.103.250 1 FULL/BDR 34w1d xxx.xxx.88.210 Vlan116
xxx.xxx.103.251 1 FULL/DROTHER 33w0d xxx.xxx.88.211 Vlan116 

 

core-sv7-nexus1# sho ospfv3 vrf tower_net nei
OSPFv3 Process ID 101 VRF tower_net
Total number of neighbors: 3
Neighbor ID Pri State Up Time Interface ID Interface
xxx.xxx.103.248 1 TWOWAY/DROTHER 00:02:28 7 Vlan116
Neighbor address fe80::116:901
xxx.xxx.103.250 25 EXSTART/BDR 00:02:37 27 Vlan116
Neighbor address fe80::116:101
xxx.xxx.103.251 25 EXSTART/DR 00:02:28 24 Vlan116
Neighbor address fe80::116:102

 

Have verified with both IPv4 and IPv6 that my MTUs are not mismatched (tried using ignore-mtu as well with no change). Looking at the logs on a particular handshake (its the same for all of them, just focusing on one for clarity) I get the following repeating over and over when talking to the non-BD/BDRs:

 

2020 Feb 7 17:30:09 core-sv7-nexus1 %OSPFV3-5-NBRSTATE: ospfv3-101 [25249] Process 101, Nbr xxx.xxx.103.250 on Vlan116 from EXSTART to INIT, ONEWAYRCVD

2020 Feb 7 17:31:16 core-sv7-nexus1 %OSPFV3-5-NBRSTATE: ospfv3-101 [25249] Process 101, Nbr xxx.xxx.103.250 on Vlan116 from INIT to EXSTART, ADJOK

2020 Feb 7 17:33:19 core-sv7-nexus1 %OSPFV3-5-NBRSTATE: ospfv3-101 [25249] Process 101, Nbr xxx.xxx.103.250 on Vlan116 from EXSTART to INIT, ONEWAYRCVD

 

and talking to the DR/BDR I get the following (repeating over and over):

2020 Feb 7 17:30:09 core-nexus1 %OSPFV3-5-NBRSTATE: ospfv3-101 [25249] Process 101, Nbr xxx.xxx.103.248 on Vlan116 from TWOWAY to TWOWAY, ADJOK

2020 Feb 7 17:30:12 core-nexus1 %OSPFV3-5-NBRSTATE: ospfv3-101 [25249] Process 101, Nbr xxx.xxx.103.248 on Vlan116 from TWOWAY to EXSTART, ADJOK

2020 Feb 7 17:31:18 core-nexus1 %OSPFV3-5-NBRSTATE: ospfv3-101 [25249] Process 101, Nbr xxx.xxx.103.248 on Vlan116 from EXSTART to TWOWAY, ADJOK

 

After a couple days, I'm completely lost. At this point figured I'd ask around to see if anyone else knows or has seen this with OSPFv3...

 

 

5 Replies 5

manokma01
Beginner
Beginner

were u able to find a fix?

Hello,

 

are you having this problem ? Have a look at the link below for troubleshooting...

 

https://www.cisco.com/c/en/us/support/docs/switches/nexus-7000-series-switches/116422-technote-ospf-00.html#anc9