Basically, after anywhere from 5-60 minutes, DNS queries fail for a few minutes, then slowly begin to resolve correctly. Then the cycle repeats. This occurs only when more than one computer is on the network. All computers on the network experiences the same sporadic DNS outage at the same time.

Wireless or wired, Linux or Windows, fresh OS install or old, browser or ping, same symptoms. Duplicated on 3 routers (not chained together, mind you) and 3 ISP's and 3 separate locations over the past several months. The only common theme is a single 5-yo WIN XP laptop which has been in use on the network throughout all this. There also may be anywhere between 1 - 10 devices hooked up wired or wirelessly at a time. The only reprieve I have from this torture is by using any VPN to an outside source - always smooth sailing.

I typically set up any router to a) use WPA2/etc security; b) MAC whitelist; c) UPNP OFF (if available); d) always update firmware when available; e) obtain DNS from ISP automatically; f) set the router to act as DHCP server for the internal network.

Adjusting channels has no effect. Any ideas?