[c-nsp] OSPFv3 Adjacency issues between 2921 and 3750

[Peter Subnovic]

Dear list members,

i am having a somewhat odd issue (again) and i am out of ideas what is
causing it.

Let's assume the following very simple topology

2921 <----> 3750G-24PS

All i want is to establish an OSPFv3 Adjacency between these two devices.
Here is where the fun (headache) begins:

The 2921 is running 15.1(4)M3 and the 3750G is running 12.2(55)SE5.

So i configured OSPv3 on both sides on the respective Interfaces and
wondered why the adjacency wont come up.

After a little bit of troubleshooting it appears that the 3750G does not
"recognize" the hello packets from the 2921. I can see in the debug output
that they are received by the switch, but the OSPFv3 Process does not
recognize them as such.

Please see the debug output below: I had debugging for IPv6 Packets and
OSPFv3 Hellos enabled. FE80::1 = 2921, FE80::2 = 3750G

Jun 30 17:00:38.347 CEST: IPV6: source FE80::1 (GigabitEthernet1/0/24)
Jun 30 17:00:38.347 CEST:       dest FF02::5
Jun 30 17:00:38.347 CEST:       traffic class 224, flow 0x0, len 80+14,
prot 89, hops 1, forward to ulp
Jun 30 17:00:41.057 CEST: OSPFv3: Send hello to FF02::5 area 0 on
GigabitEthernet1/0/24 from FE80::2 interface ID 1040
Jun 30 17:00:41.057 CEST: IPV6: source FE80::2 (local)
Jun 30 17:00:41.057 CEST:       dest FF02::5 (GigabitEthernet1/0/24)
Jun 30 17:00:41.057 CEST:       traffic class 224, flow 0x0, len 76+0, prot
89, hops 1, originating
Jun 30 17:00:41.057 CEST: IPv6-Fwd: Sending on GigabitEthernet1/0/24

As you can see, the hello packet arrives on the interface, but somehow the
OSPFv3 process on the 3750 does not "recognize" them as such. After digging
around i found the following bug and thought it could be related:

CSCtr55645

IPv6 multicast packets for routing protocols (such as OSPFv3 hello
messages) are not enqueued to CPU queue 3 as expected.

So i upgraded to 12.2(55)SE5 (where this bug should be fixed) this weekend
in the hope to resolve issue, but still the same. I am really kinda lost
here.

The 2921 does see the hello packets from the 3750 and the adjacency is in
the INIT State as i would have it expected.

show ipv6 ospf neighbor

Neighbor ID     Pri   State           Dead Time   Interface ID    Interface
1.2.3.4           0   INIT/  -        00:00:36    1040
GigabitEthernet0/1

So has anybody seen this strange behavior or has an idea what is causing
the issues? I rebooted the 3750, cleared the ospf processes on both sides,
no luck I dont wanna rule out that i maybe just missed something.

Please see below the relevant configuration of the respective Interfaces:

2921:

interface GigabitEthernet0/1
 description ===XXX===
 ip address XXX
 no ip redirects
 no ip proxy-arp
 ip flow ingress
 ip flow egress
 ip ospf authentication message-digest
 ip ospf message-digest-key 1 md5 7
 ip ospf network point-to-point
 ip ospf 1 area 0
 load-interval 30
 duplex auto
 speed auto
 ipv6 address FE80::1 link-local
 ipv6 enable
 ipv6 nd ra suppress all
 no ipv6 redirects
 ipv6 ospf network point-to-point
 ipv6 ospf 1 area 0
 no cdp enable
 no mop enabled

ipv6 router ospf 1
 router-id 1.1.1.1

=======================

3750G

interface GigabitEthernet1/0/24
 description ===xxx===
 no switchport
 ip address xxx 255.255.255.252
 no ip proxy-arp
 no ip redirects
 ip ospf authentication message-digest
 ip ospf message-digest-key 1 md5 7 xxx
 ip ospf network point-to-point
 ip ospf 1 area 0
 no keepalive
 ipv6 address FE80::2 link-local
 ipv6 enable
 ipv6 nd ra suppress
 no ipv6 redirects
 ipv6 ospf network point-to-point
 ipv6 ospf 1 area 0
 no cdp enable

ipv6 router ospf 1
 router-id 1.2.3.4
 log-adjacency-changes

If you need any additional input or show commands, please dont hesitate to
ask.

I appreciate all hints/comments.

Thanks in advance,

Peter