IPv6 seems broken on O2 side

IPv6 traffic is working between my internal network and O2’s servers, which could explain why DS Lite works. 
 

Unfortunately, it is definitely possible and happening.

Maybe the old prefix is still in use?

Or o2 has a real routing/peering problem?

Could you elaborate what you mean with the old prefix being still in use?

I will try to open a ticket, it doesn’t seem that this is something happening to a lot of other customers.

Hi @grumlu 

I am not sure if a trouble ticket will solve your problem. I would guess that the truth lies between thomasschaefer (old prefix is still in use) and klaus (Impossible from technical point of view - see DS/Lite specification) and i am not really sure if there is a solution to your case.  We reassign the IPv6 addresses every 24 hours, and i guess some of your device can’t handle that properly. 

Best regards. Matze 

Hi @o2_Matze 

The issue has been there since early December since our FritzBox auto configuration was changed (by O2) after another ticket was raised to fix a complete blackout, and all of my devices are impacted (more than 20). 
During this change, my IPv6 prefix did change, but all my devices are properly using the new one.

@grumlu You can of course give it a try and have a trouble ticket created, but I personally suspect that our colleagues in the technical department will not find any errors.

Please keep us up to date here. 

Best Regards Matze 

@o2_Matze

I have done a factory reset of my FritzBox while disconnecting it to all the devices I have in my local network, waited that everything was properly configured, and then connected to the default wifi, and I see that :

• In the event log, the IPv6 and the IPv6 prefix obtained doesn’t match. The old prefix is used while the box’ IPv6 is using the new one.
• In the IPv6 Network configuration, at the far bottom, the IPv6 prefix corresponds to the new IPv6 of my fritzbox.
• The default gateway announced by the fritzbox has the old IPv6 prefix

I’m getting a bit lost here, I don’t quite understand that the prefix obtained does not correspond to neither the prefix in the network settings and to the IP my FritzBox was assigned by O2.

Is this something that is provided during its connection to O2 network?

@grumlu I am deeply sorry, i guess our support options end here.

Your Internet is up online and running, so technical everything is okay at the moment.

Maybe one or the other member of our community has an idea how to solve your case.

Best Regards Matze 

@o2_Matze everything is not exactly working as it should, however I do greatly appreciate the support you’ve provided :)

Hopefully someone will have an idea to pinpoint the problem. 

Indicates router cascade or influences from other DNS or VPN. If Ipv4 is running, then IPv6 is functional for normal Internet applications in any case.
If the client shows problems, then you can only trace the traffic. The responsibility of a service provider ends in any case at the first router.

@Klaus_VoIP , after a factory reset of the FritzBox, with no other device on the network than a phone for example, would the proper prefix be retrieved right away by the router / FritzBox or it may take some time to depreciate any wrong configuration that could have been retrieved before the factory reset?

i have only one router, no VPN, however I have a PiHole set as my DNS. 
The reason I did a factory reset while isolating any other device from the network is in order to avoid influence from the PiHole. However, if the factory reset is not also resetting any previously assigned prefix (I’m honestly lost on how this prefix is announced to my FritzBox) directly and instead needs some time to be deprecated, that could explain my issue I guess. 

I also faced an issue recently. I disconnected my router, went for holidays and connected it again when I was back in the new year. I couldn’t access some links over VPN. Quick google search gave me the result that the problem might be in the ipv6 address from the router. I suspect, something was changed in early december from O2 side which is causing this problem because before that it was working fine. 

Strangely, I can access those links when I use my mobile phone as hotspot .

I am using O2 sim in a LTE Router (TP-Link Archer MR600 AC1200 LTE Router).

Hello @grumlu,

have you found a solution to your issue meanwhile?

Please let us know if you need further assistance.

Best regards

Giulia

Hello @balochsd,

as your issue is different (this one is about DS Lite), please remain in your other post

Best regards

Giulia

Hello @o2_Giulia ,

Unfortunately, after around 2 weeks after removing the DNS in my local network, I am still assigned a wrong IPv6 prefix, and I don’t understand how this assignment could come from my local network and not from O2’s DHCP. 
 

I tried to call O2 English support, however I am being redirected to the technical team that only speaks German (which I am still learning).

Hello @grumlu,

I think neither our English support nor our technical support could help in this case. Maybe the AVM support can help you, have you tried that already?

Best regards

Giulia

Hello @o2_Giulia 

i will reach the AVM support and come back with the results here is anything changes.

thanks

Hello @o2_Giulia 

I reached the AVM support, they confirmed me after analysing the diagnostic report that the (wrong) IPv6 prefix is provided by O2 and then propagated by my Fritz!Box.

This confirms that there is somehow an issue in the configuration data sent by O2 to my Fritz!Box :(