I have a Edimax BR-6624 Dual WAN router in my office. I've enabled load balancing to utilize both internet lines.
I want the router to use only one (specific) WAN interface when I connect to a specific IP. The reason is that the connection with the destination IP is much better through one of the two WANs. I dont know how to do this. Is it possible to do this with this kind of router?
It looks like you may be able to accomplish this using the "Routing" configuration.
The manual: http://www.edimax.us/download/manual/BR-624724_Manual.pdf
On page 32 talks about routing.
They give static routing examples for internal networking, but I suspect it should work for external routing preferences too.
You should give that a try.
eg. For destination network blah/24 use nexthop of WAN1. And then traceroute to check.
I would also like to put in a plug for pfSense http://www.pfsense.org/
If you don't mind getting your feet a little dirty, pfsense is known for being very good at doing the same things as the Edimax for much cheaper.
