The issue is the missing nameserver target in resolv. I am expecting two in the echo.
Receiving AAAA records over the only nameserver target (v4) works fine as expected - using DIG or ping. In my configuration no IPv6 nameserver target is present in resolv, hence it will never use IPv6 towards the nameserver. Only a v4 connection. The functionality of receiving A or AAAA records via v4 *or* v6 connections works fine (manually via DIG), you can see below. > root@debian:/home/user# *dig* ipv6.com ; <<>> DiG 9.18.33-1~deb12u2-Debian <<>> ipv6.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3975 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1232 ; COOKIE: 7ac359db9c31c4270100000067e50042891d6c64af1761b2 (good) ;; QUESTION SECTION: ;ipv6.com. IN A ;; ANSWER SECTION: ipv6.com. 86391 IN A 198.178.249.201 ;; Query time: 0 msec ;; SERVER: 12.34.56.78#53(12.34.56.78) (UDP) root@debian:/home/user# *dig* @2xxx:xxxx:x00:1::50 ipv6.com ; <<>> DiG 9.18.33-1~deb12u2-Debian <<>> @2xxx:xxxx:x00:1::50 ipv6.com ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 41670 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1232 ; COOKIE: 43472f7a7329ef6a0100000067e500398a9fbf9dfc4041e2 (good) ;; QUESTION SECTION: ;ipv6.com. IN A ;; ANSWER SECTION: ipv6.com. 86400 IN A 198.178.249.201 ;; Query time: 288 msec ;; SERVER: 2xxx:xxxx:x00:1::50#53(2xxx:xxxx:x00:1::50) (UDP) root@debian:/home/user# *dig* aaaa ipv6.com ; <<>> DiG 9.18.33-1~deb12u2-Debian <<>> aaaa ipv6.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40945 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1232 ; COOKIE: 076c2a8c336f64450100000067e5006f34bb754eb4e1bb7e (good) ;; QUESTION SECTION: ;ipv6.com. IN AAAA ;; ANSWER SECTION: ipv6.com. 86388 IN AAAA 2602:fa20:1:40::201 ;; Query time: 0 msec ;; SERVER: 12.34.56.78#53(12.34.56.78) (UDP) root@debian:/home/user# *dig* @2xxx:xxxx:x00:1::50 aaaa ipv6.com ; <<>> DiG 9.18.33-1~deb12u2-Debian <<>> @2xxx:xxxx:x00:1::50 aaaa ipv6.com ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 54730 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1232 ; COOKIE: 22c5fddc9d2659660100000067e500639d2839256745a712 (good) ;; QUESTION SECTION: ;ipv6.com. IN AAAA ;; ANSWER SECTION: ipv6.com. 86400 IN AAAA 2602:fa20:1:40::201 ;; Query time: 224 msec ;; SERVER: 2xxx:xxxx:x00:1::50#53(2xxx:xxxx:x00:1::50) (UDP) root@debian:/home/user# On 27/03/2025 5:23 pm, basti wrote: > Hello, > > first of all the nameservers in /etc/resolv.conf are queried in order. > That means the 2'nd one is only queried when the first one does not > answer. Even NXDOMAIN is a valid answer. > So the first one should also return IPv6 over a IPv4 connection. > > How do you query the nameserver? dig, 'getent hosts' ... ? > > > Am 27.03.25 um 05:04 schrieb Mal: >> Hello >> >> On Debian 6.1.129-1, I have a static network interface conf (no Netplan) >> with both IPv4 & IPv6 addressing and Name-servers set. >> >>> >> root@debian:/home/user# more /etc/network/interfaces >> source /etc/network/interfaces.d/* >> # The loopback network interface >> auto lo >> iface lo inet loopback >> >> allow-hotplug enp1s0 >> iface enp1s0 inet static >> address 12.34.56.78 >> network 12.34.56.0 >> netmask 255.255.255.0 >> broadcast 12.34.56.255 >> gateway 12.34.56.1 >> >> iface enp1s0 inet6 static >> address 2xxx:xxxx:x00:1::50 >> netmask 64 >> gateway 2xxx:xxxx:x00:1::1 >> dns-nameservers 12.34.56.80 2xxx:xxx:x00:1::80 >> >> >> When I query what is set in resolv.conf file, It only returns the >> IPv4 host. >> >> root@debian:/home/user# more /etc/resolv.conf >> nameserver 12.34.56.80 >> >> On another older machine (running kernel 4.9.35-v7+) with exactly the >> same configuration layout, I get BOTH the IPv4 & IPv6 addresses returned >> from resolv.conf >>> >> root@another:/home/user# more /etc/resolv.conf >> nameserver 12.34.56.80 >> nameserver 2xxx:xxx:x00:1::80 >> >> >> The IPv6 networking side has no issues - I can ssh over to other >> machines via IPv6 with no issues. And the machine is serving v6 web >> traffic fine. >> >> Mal >> >> >
