[nsd-users] Question about response source address and dynamic interfaces

Peter Hessler phessler at theapt.org
Tue Oct 9 10:12:47 UTC 2012

I use 'outgoing-interface:' in my config, per domain.  Annoying
that I can't set it globally, but I have a template I copy-and-paste for
my domains.

On 2012 Oct 09 (Tue) at 10:57:13 +0100 (+0100), Gavin Brown wrote:
:I was never able to resolve this issue, but Bert Hubert recently
:posted on a related topic. If NSD did what PowerDNS now does, this
:would resolve my problem!
:On binding datagram (UDP) sockets to the ANY addresses:
:On 16/08/2012 15:39, Gavin Brown wrote:
:>Hi there,
:>I have a FreeBSD box (hostA) running NSD. It has a management address
:>( and a service address ( It is part of a clustered
:>pair with a Linux machine (hostB) that has a management address
:>( and a service address ( DNS queries are sent to the
:>two service addresses. Heartbeat is used to co-ordinate the pairs: if
:>hostB goes offline, then the service address ( is brought up on
:>hostA so that it can answer queries, and vice versa.
:>The problem is this: without an ip-address entry in nsd.conf, responses
:>are sent from the management address ( since that is the
:>"primary" interface of the host. I can fix this during normal operations
:>by adding an ip-address entry for
:>However, during failover, queries sent to will be answered with
:>the wrong source address. Again, I could fix this using an ip-address entry.
:>But - when the machine boots, this IP address isn't assigned to hostA,
:>so if it appears in nsd.conf, NSD will refuse to start. BIND (which I'm
:>using on hostB) doesn't have this problem.
:>Has anyone else solved this problem? Or do I need to write scripts to
:>munge nsd.conf and restart it during failover/failback?
:Gavin Brown
:Chief Technology Officer
:CentralNic Ltd
:Innovative, Reliable and Flexible Registry Services
:for ccTLD, gTLD and private domain name registries
:CentralNic Ltd is a company registered in England and Wales with company
:number 4985780. Registered Offices: 35-39 Moorgate, London, EC2R 6AR.
:nsd-users mailing list
:nsd-users at NLnetLabs.nl

There exist tasks which cannot be done by more than 10 men or fewer
than 100.
		-- Steele's Law

More information about the nsd-users mailing list