We recently aquired a company and we set up conditional forwarding on the windows 2003 domain controller which also runs DNS. We then setup the DNS suffix search order on the clients(XP and 2K). This worked for about a month and then stopped. We haven't changed anything and i've checked all options. The lookup only works if I append the domain. Example: If i want to ping hostA I need to type "ping hostA.domain.loc" If i simply type "ping HostA" it times out. It used to work though.
The domain controller which runs DNS is on Windows 2003 standard. Clients computers are mostly on XP whith a few exceptions. We have a site to site VPN tunnel between offices which is working fine.
How do I go about further troubleshooting this?