To help with the diagnostics of one of my internet connections, I've used load balancing to route all traffic from one PC through WAN2.

But I'm finding that this breaks my internet connection. I'm fairly sure that what is happening is that the vigor is using WAN1's DNS servers with a WAN2 session, as I can restore connectivity if I manually set the DNS so that the primary is WAN1's primary and the secondary is WAN2's primary.

Its pretty messy, and obviously results in a lot of failed DNS requests.

Can anyone help? Have I set things up wrong or is the Vigor getting it wrong?

You are not the first to point this problem with load balancing not getting DNS requests routed through the correct WAN port.
Maybe one day we may actually get a Draytek router that does what it says it does..

MarkieBrown wrote: You are not the first to point this problem with load balancing not getting DNS requests routed through the correct WAN port.
Maybe one day we may actually get a Draytek router that does what it says it does..

Wouldn't that be nice. In the meantime, with dual WAN setups I always use the OpenDNS servers for both connections. They are:

208.67.222.222
208.67.220.220

Thanks for the advice. I finally got it going with Google's version of open DNS. I might switch to these though - I reckon Google knows enough about every one of us already.

Now if only I could get the Draytek to hold onto an ADSL sync when the line quality has its off days.....