(In reply to comment #57)
> since it updated, BIND stop responding to requests IPv6 regularly. we have
> found these errors:
> Sep 1 04:02:01 tree named[8364]: client.c:1334: unexpected error:
> Sep 1 04:02:06 tree named[8364]: client.c:1334: unexpected error:
> Sep 1 04:02:11 tree named[8364]: client.c:1334: unexpected error:
(In reply to comment #57)
> since it updated, BIND stop responding to requests IPv6 regularly. we have
> found these errors:
> Sep 1 04:02:01 tree named[8364]: client.c:1334: unexpected error:
> Sep 1 04:02:06 tree named[8364]: client.c:1334: unexpected error:
> Sep 1 04:02:11 tree named[8364]: client.c:1334: unexpected error:
It seems you are affected by bug #518866.