In the messages log of my BIND DNS name server I saw a lot of errors like this:
named: network unreachable resolving 'ns.domainnetwork.se/AAAA/IN': 2001:6b0:e:3::1#53
named: network unreachable resolving 'ns3.domainnetwork.com/AAAA/IN': 2001:503:ba3e::2:30#53
I have found that possible source of messages of this kind is that I have disabled IP_V6 on server. Proposed solution is to put to the file /etc/sysconfig/named the following line (to disable IP_V6 on bind):
After that restart of named service required.