[vserver] ISC BIND does not listen on IPv6 address

I recently added an IPv6 address to a vserver running BIND.

But BIND doesn't mind.

Using "strace -s 1500 -o /tmp/trc -f named -d 10 -p 54 -f -g"
I found out it opened /proc/net/if_inet6 and just ignored IPv6 afterwards.
(using port 54 here to not interfere with the productive dns)

So I added interface lo - ::1 - /128 in /etc/vservers .

Now I get
        29-Oct-2016 10:49:06.912 using default UDP/IPv4 port range: [1024, 65535]
        29-Oct-2016 10:49:06.912 using default UDP/IPv6 port range: [1024, 65535]
        29-Oct-2016 10:49:06.913 listening on IPv4 interface lo, 127.0.0.1#54
        29-Oct-2016 10:49:06.913 listening on IPv4 interface eth0:0, 212.9.165.46#54

so I'm missing something like
        listening on IPv6 interface eth0<*>, 2001:14b0:203:4000::6e73#54

Other stuff:

BIND compiled with "--enable-ipv6"

"listen-on-v6 { any; };" is set, changing it to "listen-on-v6 { 2001:14b0:203:4000::6e73; };"
does not change anything.

/etc/default/bind9 is
        OPTIONS=""

netstat -tulpen
        Active Internet connections (only servers)
        Proto Recv-Q Send-Q Local Address Foreign Address State User Inode PID/Program name
        tcp 0 0 212.9.165.46:53 0.0.0.0:* LISTEN 0 13771626 21924/named
        tcp 0 0 127.0.0.1:53 0.0.0.0:* LISTEN 0 13771624 21924/named
        tcp 0 0 212.9.165.46:54 0.0.0.0:* LISTEN 0 13932904 22117/named
        tcp 0 0 127.0.0.1:54 0.0.0.0:* LISTEN 0 13932902 22117/named
        tcp 0 0 127.0.0.1:953 0.0.0.0:* LISTEN 0 13771627 21924/named
        tcp6 0 0 ::1:953 :::* LISTEN 0 13771628 21924/named
        udp 0 0 212.9.165.46:53 0.0.0.0:* 0 13771625 21924/named
        udp 0 0 127.0.0.1:53 0.0.0.0:* 0 13771623 21924/named
        udp 0 0 212.9.165.46:54 0.0.0.0:* 0 13932903 22117/named
        udp 0 0 127.0.0.1:54 0.0.0.0:* 0 13932901 22117/named
        udp6 0 0 :::35767 :::* 0 13933799 22117/named

Inside the vserver I can set up
        echo "ACK" | nc -6 -l -p 54 -v
and run
        nc 2001:14b0:203:4000::6e73 54
from
        - the vserver itself
        - the vhost
        - a completely different piece of hardware
and get my "ACK".

The listener can't be launched on port 53 as long as BIND runs:
        nc: Address already in use
which is quite fine and indicates the port is held open by BIND.

I can run (vserver):
        nc -6 -l -p 53 -u -v
and try from outside
        dig @2001:14b0:203:4000::6e73 soa uoduouvfdouvdf +short
with the result of
        Listening on [:::] (family 10, port 53)
        �9 uoduouvfdouvdf)�9 uoduouvfdouvdf)�9 uoduouvfdouvdf)

so, the communication on IPv6 port 53/udp just works fine.

At last I tried
        strace -s 200 -f named -p 54 -f -g
and
        dig @2001:14b0:203:4000::6e73 soa uoduouvfdouvdf +short -p 54
result:
        absolutely no reaction on the BIND side.

-- 
LiHAS - Adrian Reyer - Hessenwiesenstraße 10 - D-70565 Stuttgart
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