Question : Why does our local DNS stop resolving intermittently after I changed the IP addresses?

We have a Win 2003 SBS with DNS for the IIS server on it. Recently, I changed the IP addresses of all of the machines on the network so they make sense (they were all over the place earlier).
After I did this, everyone on the network found that occasionally they had to do a connection repair on their computer to be able to access our local IIS server. The internet still works on all computers and everyone can ping everyone else when this happens.

The workstations all run Windows XP SP3. All references to the old IP addresses were changed to the new ones in the DNS server. All machines have fixed IP addresses.

I think it may be something to do with the DNS cache but I can't figure out why this would start happening when the IP addresses were changed.

Answer : Why does our local DNS stop resolving intermittently after I changed the IP addresses?

This is rather bad since you mention this is an SBS domain:

> The configured DNS servers for the LAN NIC are:
>  - 10.1.1.1 (the server in question)
> - 139.130.4.4 (Telstra's DNS server)

Clients and servers participating in an AD Domain should only use DNS servers that are able to answer for the AD domain. In short, they must use the SBS server for DNS and nothing else. If you want or need to use Telstra's server you can add it to the Forwarders tab in the properties for the DNS server (DNS Console).

It would explain this:

> C:\>ping able.serv.local
> Ping request could not find host able.serv.local. Please check the name and try
> again.

If "ping" asked Telstra's DNS server and they said "what? No. Doesn't exist" your system will remember that for 5 minutes before attempting to resolve the name again. Once it tries again you're back to pot-luck on whether or not you get the correct reply from the right DNS server.

Chris