[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: bind9 needs sometimes a restart after resume from suspend

Karl E. Jorgensen wrote:
> I wonder... What exactly does "bind not responding" mean? any command
> that reproduces that would be handy.
> As this is happening in relation to suspend/resume, this would imply
> that network interfaces go down and up too. So perhaps bind is failing
> to detect the re-arrival of network interfaces?
> The output of a command like "sudo netstat -nlp | grep bind" while
> bind is not responding would be instructive. And then compare/contrast
> with the scenario of a "working" bind...

I think that is a good debugging direction.  For reasons I haven't
looked into BIND will bind to specific addresses.  There is always  Plus there will be one for each interface.


  $ netstat -na | awk '$NF=="LISTEN"&&/:53/'

With this example output from a system.

  tcp        0      0*               LISTEN
  tcp        0      0  *               LISTEN
  tcp6       0      0 :::53684                :::*                    LISTEN
  tcp6       0      0 :::53                   :::*                    LISTEN

It may be that something is dropping the network offline and the
suspend-resume is simply cycling the network off and on again and
restoring the network connection.  Maybe the root cause isn't BIND but
rather that the network has gone offline.

  $ ip addr show | awk '$1=="inet"'
    inet scope host lo
    inet brd scope global br0

I would also want to know what is in /etc/resolv.conf to know if it is
configured for the local nameserver.  And also what "hosts" entry is
listed in /etc/nsswitch.conf to see how it is configured.

  $ grep nameserver /etc/resolv.conf

  $ grep hosts /etc/nsswitch.conf
  hosts:          files dns

Lastly this *shouldn't* be related to any DNS lookups but the contents
of /etc/hosts is the "files" part in the above.  It is possible that
contents of /etc/hosts might be confusing the issue of thinking bind
isn't working properly.  Shouldn't be since it apparently works after
a suspend-resume but mentioning it here for completeness anyway.


Attachment: signature.asc
Description: Digital signature

Reply to: