I'm wondering if my pi-hole installation is working correctly with IPv6 because i noticed some things. I had to reinstall my raspberry pi some time ago. Since then only a relative low number of IPv6 queries occur in comparison to my installation before.
If i try 'dig -6 google.com' on any windows machine i get timeouts:
dig -6 google.com ; <<>> DiG 9.16.13 <<>> -6 google.com ;; global options: +cmd ;; connection timed out; no servers could be reached
ipconfig -all DNS-Server . . . . . . . . . . . : 192.168.0.2 fd00::70fc:7114:a1f6:9b24
If i try them on the raspberry pi directly it's workling fine:
dig -6 google.com ; <<>> DiG 9.11.5-P4-5.1+deb10u3-Raspbian <<>> -6 google.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 48012 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1472 ;; QUESTION SECTION: ;google.com. IN A ;; ANSWER SECTION: google.com. 300 IN A 184.108.40.206 ;; Query time: 31 msec ;; SERVER: ::1#53(::1) ;; WHEN: Fr Apr 30 10:26:25 CEST 2021 ;; MSG SIZE rcvd: 55
Is it possible that IPv6 requests are blocked via firewall or something. Do i have to add some iptable rules? The query from raspberry pi does show up in the pihole.log, query from windows machine doesn't.
I also noticed a high number of queries to ' ipv4only.arpa' since some days. After some research, I interpreted this domain to be used for DNS64 and especially when there is no true dual stack.
My ISP is telekom and i've got a real dual stack in my opinion.