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IPv6 neighbor status=failed

Posted: Tue Jan 07, 2020 11:09 pm
by ginojo
Hello,

Recently we moved our infrastructure to a new datacenter and immediately we started getting ipv6 connectivity issues. At first I was blaming the ISP, but after a lot of troubleshooting I think it might has something to do with the Mikrotik gateway (CCR1009-7G-1C-1S+).

We have a regular /64 where ::1 is the gateway of the ISP and our mikrotik is ::2. The ISP routes an additional /48 subnet over the provided /64 to ::2. On the mikrotik we split the /48 into several /64 and advertise it in different vlans. We have a static route to 2000::/3 set to go to the ISP ::1.

With the ipv6-addresses disabled in the vlans, we can ping ::1 and the rest of the internet from the mikrotik without packet-loss or whatsoever. But when we enable the vlan gateway addresses the mikrotik begins to struggle. 'Flows' of packet-loss occur from hosts to the internet and vice versa. (defining 'flows': connectivity is ok and abruptly gone for a 10-20 seconds).
I can see in the IPv6 neighbors that the ::1 is changing regularly to status=failed and the mac address disappearing. I have no clue why, because when I ping ::1 from the mikrotik seems to be ok.

When keeping a ping running from the mikrotik to ::1 the connections seems to be failing less often (but still too often).

Do you have any ideas about what is going on here or suggestions on how to troubleshoot further?

Kind regards,
Gino

Re: IPv6 neighbor status=failed

Posted: Wed Jan 08, 2020 8:33 am
by mkx
A far shot: do you have IGMP snooping enabled on CCR? I've had similar issues in my network after I enabled IGMP snooping and disabling it returned full IPv6 functionality.
Current implementation of IGMP snooping on ROS interferes with IPv6 (seems that it blocks routing advertisements ... not entirely, but mostly). According to posts on different forums also other vendors have had their share of problems in that field, but most of vendors fixed the problems so far. MT seems to largely neglect IPv6 right now).

Re: IPv6 neighbor status=failed

Posted: Wed Jan 08, 2020 12:18 pm
by ginojo
Unfortunately I have no IGMP snooping enabled on the ccr. Thanks for the suggestion

Re: IPv6 neighbor status=failed

Posted: Sat May 02, 2020 9:33 pm
by mafiosa
I too have this issue yet so solution! Mikrotik devices are so buggy! Will replace them soon with edgerouters.

Re: IPv6 neighbor status=failed

Posted: Sun May 03, 2020 2:44 am
by idlemind
Any chance you could post an export with hide-sensitive on?

/export hide-sensitive 

I don't have a CCR and but v6 is working just fine on the hardware I still run with RouterOS. Like others have said IPv6 simply isn't a priority with Mikrotik. I've moved every purchase possible to other platforms like Ubiquiti largely for that reason lately.

Re: IPv6 neighbor status=failed

Posted: Fri Dec 04, 2020 2:24 am
by charliehu
Hello,

I have CCR2004 routers, and i experience the same. In ipv6 neighbor list, ipv6 addresses going to fail within after a short time.

Re: IPv6 neighbor status=failed

Posted: Thu Mar 02, 2023 1:33 pm
by fljarad
Hello,

I have CCR2004 routers, and i experience the same. In ipv6 neighbor list, ipv6 addresses going to fail within after a short time.
We have the same issue - any resolution/sugestions?

Re: IPv6 neighbor status=failed

Posted: Fri Mar 31, 2023 10:50 pm
by srTeCHNoiD
Up. Problem is actual for 7.8. What reasons can be, if no IGMP snooping in transit?