Unbound error: can't bind socket: Can't assign requested address for x.x.x.x

[wbond]

I setup dual wan a week or so ago and came home today to find our primary internet connection down.  We still had internet access so the system had failed over and seemed to be working.  In checking the logs I noticed that the DNS resolver log was showing the following over and over several times a second.

Jun 27 20:05:02  unbound  49531:6  error: can't bind socket: Can't assign requested address for 174.xxx.xxx.xxx

The IP address in the log was the IPV4 of the primary WAN before it went down.  The default gateway is DSL pppoe and the secondary is a cable connection.

I'm using pfSense 2.3.1-RELEASE-p5 (amd64) and the DNS resolver in non-forwarding mode.  I have default gateway switching enabled.  In testing I've done since setting it up it seems to failover correctly.  While I was getting this in the resolver log DNS seemed to be working ok.  When the default gateway came back up the resolver log went back to normal.

Has anyone seen this before?  Do I have something misconfigured?

Thanks in advance.

[cmb]

If you have specific interfaces bound, and their IP goes away, it'll do that. Best to either let it bind to all, or only specify LAN IPs.

[wbond]

You nailed it Chris.  I had it bound to only my internal networks and localhost under Network Interfaces, and only WAN/WAN2 under Outgoing Network Interfaces.

Thank you.