We are using ISA 2004 in our company, network wide. We have a group of PCs in their own subnet that are connected to their own network in ISA. These PCs are located on our Repair Facility network and are constantly accessing the Microsoft Windows Update web site. The updates files for download can vary ofcourse because the OS's range from Windows 98/ME/2000/XP.
When we had our ISA 2000 server in place, by default it would cache every single windows update that was downloaded. Once 1 machine downloaded the update it would remain in the cache.
Now with ISA 2004 it seems that the default cache rules, and even after modifying the cache rules the Windows Updates only stay cached for a short period of time.
Anybody messed with the caching enough to make some suggestions?....Thanks.
SUS works in conjunction with Group Policy and the Automatic Updates service on Servers/Clients.
Once SUS is installed and configured on a server in your Local network, you then create a new GPO or modify an existing one to incorporate clients/servers to receive updates from the SUS server (http://sus_server_name)
For what it's worth if you try it you will find that the Microsoft updates are cached. I say this as unless my internet connection can download 75Mb in less that a second they must be. (and it can't unfortunately)