IPv6 stopped working...

[Leone]

As of last Saturday I noticed that IPv6 is not working reliably. I have opnsense router and Rogers modem is in bridge mode, I am on Ignite 500 package. I did not change any settings or upgraded router. All is in the same state as it was for few month and ipv6 worked ok, now all of a sudden I see that interfaces are assigned correct ipv6 addresses and sometimes after router and modem reboot it even work for like 10-30 minutes but eventually it will stop working. Also after reboot it takes very long time to get addresses for ip6 (ip4 gets them quickly). Do I need to change any settings? I used to have prefix size /56 but now I rolled back to /64 in hope that it will resolve the issue (it did not). Please advise. Thank you!

***EDITED LABELS***

[-G-]

I am also a Bridge Mode user with 1.5 Gigabit (DOCSIS) Internet and am not experiencing any issues with IPv6 connectivity.  I am currently using pfSense, and also recently tested with an OpenWrt router that I would have used as a backup in case I ran into problems with my upgrade to pfSense 2.7.1-RELEASE.  I am able to request both /64 and /56 prefixes.

All tests also pass on https://en.internet.nl/ and https://test-ipv6.com/

When the Ignite Gateway is in Bridge Mode, it still has internal services running.  If you log into it and go to "Gateway > Connection > Rogers Network", can you confirm whether it is able to obtain an IPv6 Address on its WAN interface?

I have also tested OPNsense in the past and never experienced any IPv6 connectivity issues, at least not with the relatively simple configurations that I was using.

[Leone · Accepted solution]

Looks like something was fixed, maybe some switches were rebooted on Rogers network, problem seems to be resolved. Not fixed 😞

[Leone]

Just happened again 😞 ipv6 is down after few hours ::::((((

[Datalink]

@Leone you need to discuss this with a Level II tech.  Level I techs can't help as they won't have any idea of what you're talking about.  So, you can either get thru to a Level II tech, or, send a message to the moderators at @CommunityHelps.  In either case, a report is required to be sent to the Network Operations Center, or to the Network Engineering staff.  

The first question of the day is whether there is any possibility of a packet loss situation which is usually due to external cabling failures.  If you're convinced that this is an IPV6 issue, then press on. 

Rogers has a long history of sporadic IPV6 failures due to mistakes / problems with the CMTS IPV6 configuration.  These failures manifest themselves in one or both of the following:

1.  The CMTS fails to issue an IPV6 prefix; or/and

2.  The CMTS does not allow returning IPV6 data to reach the modem and the connected devices.  This will look

      like an IPV6 failure when you attempt to run an IPV6 online test.

Level I techs will not understand this and will automatically blame your opensense router  Their solution will be to return the modem to Gateway mode and reboot the modem.  Problem solved...... not.

So, if you decide to call tech support, your task is to ask if the Level I tech can resolve a CMTS IPV6 problem?  If yes, then get on with it. If not, pass you on to a Level II tech so that this can be resolved.  That should get you to a Level II tech.  

What you can do is:  

1.  Run an IPV6 trace to anywhere, google for example:

     Tracert -6 www.google.com

2.  The first hop is the modem.  The second hop is the CMTS.  

3.  Copy the CMTS IPV6 address from the trace.  If you select or highlight the trace, you can use Ctrl c to copy the trace data and then paste it notepad so that you can isolate the CMTS IPV6 address. 

4.  Ping the CMTS IPV6 address

     Ping -n 86400 2607..........

That will run a 24 hour test, pinging the CMTS with an ICMP ping.  Looking at the trace results will tell you if an IPV6 failure has occured.

Now, fwiw, if you use Windows Powershell, you can produce a ping test or trace with a timestamp that is printed to a file, so, if you're running a 24 hour test, you will end up with a results with a timestamp that you can point to for failure points.  With that data, a Level II tech, moderator, or NOC staff member should be able to track down the failure events. 

To run a powershell session, have a look at the following post and speedread down to the IPV4 test session with powershell.  The same procedure applies, but, in your case you're substituting the IPV4 ping for an IPV6 ping.  

https://communityforums.rogers.com/t5/Internet/Extremely-slow-internet-amp-TV-in-the-evenings-since-...

Having said all of that, you need to be absolutely certain that you don't some opensense bug lurking around in your router.  You need to be on solid footing prior to chasing down a potential CMTS IPV6 bug.  Have you checked the opensense forum for any IPV6 issues related to the current build that you're running?  Has there been any update that might have affected IPV6 behaviour?

https://forum.opnsense.org/

[-G-]

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@Leone wrote:

Just happened again 😞 ipv6 is down after few hours ::::((((

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That IPv6 suddenly stops working for you suggests a routing issue where, for whatever reason, Rogers stops routing packets destined for your PD to your router.  It could be a problem on Rogers' side.  It could be a problem on your end as well.

Does OPNsense have a Do not allow PD/Address release option in its DHCPv6 client config that you can enable?

That you have problems obtaining IPv6 addresses on startup also points to a potential problem with the operation of the DHCPv6 client on your OPNsense box.  I have never had to troubleshoot any such issues yet so I'm not sure how to advise you, if this really even is an underlying cause of your stability issues.

You also really need to pour through your logs to see what is happening when you lost IPv6 connectivity.

[ta1835]

I don’t have my Ignite gateway in bridge mode but I’m also having lots of IP6 errors for last couple weeks. I’d love to try bridge mode but have been reluctant due to possible issue with Ignite TV. Do you have any recommendations on best set up if I were to give this a try? Getting new Orbi 970 routers today, now would be good time to switch to bridge mode.