I am running a network of more than 300 nodes all on Windows XP, on the Server we have recently migrated to Windows Server 2003 and ISA Server 2004 but there is no Domain Environment we are running a Workgroup Environment.
What happens is that everything works fine for a couple of days, then all of a sudden, the ISA Firewall Clients on the Client Computers they are unable to Resolve the Server Name and therefore everything stops working (Clients cannot browse Internet, Outlook etc.)
When we open the Firewall Client and click on UPDATE, it does not resolve the Server Name and Refresh Operation Fails, If I put the IP Address of the Server instead of the Server Name 192.168.0.1 then refresh operation is successful, but things don't work in this case as well and a Red Exclamation mark appears on the Firewall Client.
I have One Access Rule Implemented, which is:
Allow ---> All IP Traffic ---> From Internal and LocalHost ---> To External and Anywhere ---> Applicable for All Users
If I play with the ISA settings for a while things sometimes start working again, but after half an hour or so it happens again and the Client is unable to Refresh.
Now this is what I did, I installed Windows Server 2003 again and ran dcpromo and then configured a Scope in DHCP and then installed ISA Server 2004 (Standard).
What is happening right now is that all the firewall clients are not being updated, when we press the update button it says, Could not locate ISA Server, the ISA Server might be down or not available on this network.
When I ran the fwctool, it is also not locating the ISA Server.
Whereas, when we disable ISA Firewall Client on the Client Computers and change the proxy in Internet Explorer from SERVER:8080 to 192.168.0.1 Port 8080 everything is working fine.
The only problem that remains on my network is that ISA Client is not being updated/refreshed and is unable to locate the ISA Server.
I'm a newbie, please some urgent help will be highly appreciated. We are running a workgroup environment.