IPV6 issue apon internet connection restore

I have noticed an issue with pihole. Recently I lost internet connection. Once internet connection was restored, I had ipv4 dns connection, but I did not have ipv6 connection. It required me to completely reboot RPI in order to restore IPV6 DNS. This issue did not exist before the beta and subsequent release of new Pihole version.

The beta is over (because the new version was released) so I moved the topic to the Help section.

Does the issue still persists? Do you have any connectivity issues at the moment?

It is fixed whenever i reboot the RPI. I can replicate the issue by rebooting my router. Once connection is restored, I attempt to access DNS over ipv6 of the pihole, and there is no dns resolution. Only resolution for ipv4. Subsequent rebooting of the RPI restores both ipv4 and ipv6 dns. Either one of two things is happening.

  • Pihole does not restore ipv6 DNS upon connection restore.

  • Or RPI is not properly restoring ipv6.

I need someone else to test this issue to see if they also experience the same problem. The issue wasn't present until after updating Pihole to the new release(or i didn't notice the issue until now).

The steps I use to confirm there is no DNS traffic traversing via IPV6 is doing a simple test on

or running a test on
http://en.conn.internet.nl/connection/

It will confirm there is no ipv6 DNS.

When I restart the RPI the Ipv6 dns traffic is working properly while visiting these sites.

I guess it is the RPi that is causing the issue here, but we can verify this easily: Instead of restarting the entire RPi, you could try

pihole restartdns

This will restart all Pi-hole components. If this does not resolve the issue, but rebooting the entire system does, then it is definitely a system issue.

Does the gui option for "restart DNS resolver" do the same thing?

Yes, good that you mention it. I'm using the GUI not too often myself :wink:

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There's really no such thing as IPv6 DNS.

IPv6 uses AAAA records to resolve a hostname to an IPv6 address but that's about it. Any DNS server will give you an AAAA record result when queried, it's not something only a DNS server listening on IPv6 can do.

I think your issue is on the network level, you don't have IPv6 connectivity so you can't access an IPv6 address when given one from an AAAA query.

Correction. My network is a dual stack. When Ipv6 address is properly working, on
ipleak.net
I see the WAN IP addresses for both ipv4 and ipv6. When it is not, I only see the IPV4 address of my WAN. I truely hope this clarifies it for you. BTW I am also running unbound.

That confirms my suspicions. The issue is with the router or the network and not with Pi-hole.

Are there any settings you could think of that need to be enabled on the RPI itself that would allow for IPV6 to respond once the connection is restored? I am wondering if there is a setting I need to enable in /etc/sysctl.conf that might change how IPV6 is handled on changes. It seems to be directly related to the RPI itself because the same thing is happening with another RPI i have on the same network. (not used for actual internet connection though). it also loses ipv6 connectivity. I would not have noticed this if one of the piholes wasn't being used on my main network.