OSPFv3 issue 2 CCR's will not form adjacency

RouterOS Forwarding Protocols
1

Hi,

We have two CCR 1036’s running v6.34.3
They WILL form OSPFv2 adjacency just fine.

The WILL NOT form OSPFv3 adjacency and stay stuck in Exstart and dropping from Full to 2-Way.
I’m trying to bring IPv6 up on these new links hence the OSPFv3.

The two routers are interconnected via a pair of AirFiber 24’s
I do NOT believe this to be a MTU issue as
a) OSPFv2 is working
b) the AirFibers support MTU 9000 and the CCR’s are 1590

relevant config snips

psr07:
/routing ospf-v3 instance
set [ find default=yes ] router-id=XXX.XXX.XXX.28
/routing ospf-v3 interface
add area=backbone interface=eth11-uplink network-type=point-to-point ← To Cisco 3560G WORKS
add area=backbone interface=eth2-af24-505-5301 network-type=point-to-point ← BROKEN

/ipv6 address
add address=XXXX:XXXX:a000:105::2/126 advertise=no interface=eth11-uplink
add address=XXXX:XXXX:a000:106::1/126 advertise=no interface=eth2-af24-505-5301
add address=XXXX:XXXX:a000:103::1/126 advertise=no interface=eth3-af24-505-6001

set [ find default-name=ether2 ] l2mtu=1590 name=eth2-af24-505-5301

log

mar/20 21:45:12 route,ospf,info OSPFv3 neighbor XXX.XXX.XXX.27: state change from Full to 2-Way
mar/20 21:45:13 route,ospf,info Database Description packet has different master status flag
mar/20 21:45:13 route,ospf,info new master flag=false
mar/20 21:45:13 route,ospf,info OSPFv3 neighbor XXX.XXX.XXX.27: state change from Full to 2-Way
mar/20 21:45:14 route,ospf,info Database Description packet has different master status flag
mar/20 21:45:14 route,ospf,info new master flag=false
mar/20 21:45:14 route,ospf,info OSPFv3 neighbor XXX.XXX.XXX.27: state change from Full to 2-Way


psr06: config / log

/routing ospf-v3 instance
set [ find default=yes ] router-id=XXX.XXX.XXX.27
/routing ospf-v3 interface
add area=backbone interface=eth1-af24-5301-505 network-type=point-to-point

/ipv6 address
add address=XXXX:XXXX:a000:106::2/126 advertise=no interface=eth1-af24-5301-505

/interface ethernet
set [ find default-name=ether1 ] l2mtu=1590 name=eth1-af24-5301-505

logs
03:49:09 route,ospf,info OSPFv3 neighbor XXX.XXX.XXX.28: state change from Loading to 2-Way
03:49:10 route,ospf,info OSPFv3 neighbor XXX.XXX.XXX.28: state change from Loading to 2-Way
03:49:11 route,ospf,info OSPFv3 neighbor XXX.XXX.XXX.28: state change from Loading to 2-Way
03:49:12 route,ospf,info OSPFv3 neighbor XXX.XXX.XXX.28: state change from Loading to 2-Way
03:49:13 route,ospf,info OSPFv3 neighbor XXX.XXX.XXX.28: state change from Loading to 2-Way


Thank you for your help.

2

Hate to say it, but considering the issue you’re having in the other thread with getting stuck in EXSTART with OPSFv3 between a CCR and Cisco switch is identical to this one which involves only CCRs, i think you definitely have some kind of MTU issue or bug related to MTU.

Can you cable the two CCRs directly to each other and see if the issue goes away?

3

I would seriously check the AirFiber code version and test MTU throughput. There seem to be a number of threads in the Ubiquity forums that claim jumbo frames are enabled but not actually passed…

https://community.ubnt.com/t5/airFiber/AF24-MPLS-Issue/td-p/1099827

4

Hi, Yes, I read that thread. I’m running version 3.2 of the AF code.

Here is the full topology, three sites, A, B, C

A ↔ B CCR to Cisco, OSPF v2 works, OSPF v3 does not, AF24 link

B ↔ C Cisco to CCR, OSPF v2 works, OSPF v3 works, AF24 link

C ↔ A CCR to CCR, OSPF v2 works, OSPF v3 does not, AF24 link

All AF’s are code level 3.2
All CCR’s are 6.34.3
Cisco is IOS 15.x

Network type is Point to Point for OSPF
NBMA doesn’t work on the affected links.

Its a fun problem :neutral_face: Thanks for the help

5

I thought I would post a follow-up / resolved message.

First THANK YOU TO MIKROTIK SUPPORT / ENG team.

The issue ended up being an interesting corner case bug in the OSPFv3 code of RouterOS
I’ve tested 6.36rc10 and it’s fixed in that version.

All OSPFv3 sessions are now operating as expected.