DNS acting up

[vun]

For the past months I've been losing internet connection every now and then. Sometimes it can work perfectly fine all day but start acting up during the evening, other times, like today, it'll go bat**** whenever it feels like it.

I've tried changing DNS to Google's DNS service and OpenDNS, though I'm not sure whether it actually helped or not. I've tried flushing DNS cache and a few other steps to stop this, but it doesn't seem like it works.

Where the problem is I can't say for sure, but I doubt it's on the ISP's end, more likely to be the router as both my desktop and my laptop go out at the same time, desktop is wired and laptop is wireless.
However, I haven't heard anyone else in the household complain, so I'm worried it's something on my end. Even though it happens over two computers, they're both mine so they have a lot of the same software installed.

Router is a Linksys WRT120N for now, but I'll see if anyone else gets disconnects, then I'll have it changed and hope that fixes it.

Hoping anyone here can be of assistance as there seems to be a lot of competent members here.

[mike]

Tricky ...

You've got the DNS set on the machines themselves and not on the router ? If you just let the machines obtain their address automatically, you'll get whatever the router decides should be the DNS settings (unless you override these). It may be worth just letting the router decide what the DNS should be (either your ISP's DNS servers or the router itself as a caching/forwarding DNS server), as an experiment.

The trouble with using OpenDNS and/or Google's DNS service is that it breaches the (admittedly conservative) principle of ensuring that a client's DNS recursive server is on the same network segment or no more than a hop or two away. Whilst many people do this without an issue, it does leave the DNS service more vulnerable to any transient network issues anywhere between you and the server. If you want to use OpenDNS, make the change on the router and use the router as a DNS server.

In this case, I'd not be inclined to blame the router first.

[vun]

I usually let the machines and router obtain DNS automatically, when I try to use Google DNS or OpenDNS I set that on the machine as I don't feel as comfortable messing with the router settings when there are other people on the network.

Also, how do you use the router as a DNS server? Is it as simple as overriding the default DNS values (0.0.0.0) with the another DNS?
I also won't use OpenDNS simply because their way of making money interrupts my flow. In Firefox on my ISP's or Google's DNS I can just type 'geekhack' if I want to go to here, but with OpenDNS it would redirect that to the OpenDNS guide unless I wrote the full address.

Another problem with using anyone else's DNS is speed, I did some tests and my ISP's DNS came out over 50% faster than Google's.

What would be the easiest way to determine where the problem lies, and how would I go about doing it?

Edit: Just happened again, that's three times today.

Edit 2:
I'm thinking it's the router; I lost connection again and went to power cycle the router, but before I did so I checked the computer we have standing next to the router, and it seemed like it had lost connection as well. I didn't see the warning sign in the systray so it had probably just regained connection, but WLM was in the process of reconnecting.
Guess the router needs to be changed, either that or we need to have a chat with the ISP.