We have here a small windows 2003 SBS network. The sharepoint intranetsite is hosted on the server. The DNS however, is handled by a (Zyxel) router. The problem is that sometimes none of the client computers can find the companyweb intranetsite, usually the problem resolves itself within a few hours. I checked the ip addresses of the clients, but it seems they are correctly handed out by the router. I am able to browse the network. How can I begin to troubleshoot this? I haven't the faintest idea where the problem may be located.
The only DNS server the client computers use should be the SBS 2003 server. Change the Client PCs to point to the server and not the router.
The problem is your router will pass on DNS requests to your ISP, which dosent know about your internal network, or about any internal web sites hosted on your server.
By using the DNS on your SBS server your client computers will be able find your internal sharepoint site. For external websites like serverfault.com your SBS server will either use Forwarders which will point to your ISPs DNS servers, or it will use Root Hints.
If you put both the SBS server ip address and the router ip address into the client pcs DNS settings you will still run into problems. As I said only use the SBS server for DNS on your client computers.
Ideally DHCP should be handled by the SBS server aswell.