Question : Server not found errors

I have the following problem: when I open web pages in FireFox or Internet Explorer sometimes I get a "server not found" error, then I click "try again" once or twice and it works again. This happens quite often so I don't think the problem is caused by the web site servers, and it happens on many web sites. However does not happen on all sites, It seems I don't have this problem with pages located in the Netherlands (where I'm located too). I checked with someone who has the ISP as I do, if he also had the problem, but that is not the case.

The situation is as followes: I have a Windows XP SP2 computer and a laptop running WinXP SP2, both are connected to a cable Internet connection with a Draytek Vigor 2200 router. Both have the problem. The problem seems to be browser independed as it happens in Firefox and Internet Explorer.

I tried to set the IP address of the DNS server (before it was the routers ip) to be forwarded to the computers connected to the router. I tried both my ISP DNS server and a public DNS server, neither of them fixed the problem.

Any ideas?

Answer : Server not found errors

if it happens on both computers, then it is a networking issue
i would start by taking your router out of the picture.  connect one computer directly to your cable modem and see if the problem occurs.  if the problem still occurs, it could be a bad ethernet cable, or a bad cable modem.
if the problem does not occur when you are directly connected to the cable modem, the problem is most likely with your router (although it could be a bad cable so make sure you try swapping out the cables first).  it could be a bad router, or it could be that your router needs to be configured differently, or perhaps a hard reset or firmware upgrade would resolve the issue.