Believe it or not, our corporate network still uses ISA Server 2000 (in a Windows Server 2003 machine) to enable / control Internet access to / from it.

I was asked recently to configure that ISA Server to create a site-to-site VPN for a new branch in a office about 25 km. away from it. The idea is basically to enable not only computers, but also Palm devices (WiFi-enabled, of course), to be able to see other computers in both sites.

I was also told that a simple VPN-enabled wireless AP/router (in this case, a Cisco WRV210 unit) should be enough to establish communications with the main office. To be fair, the router looks easy to configure; it was confusing at first, but further understanding of how site-to-site VPNs work cleared all doubts about it.

Now I need to make modifications to our ISA Server in order to recognize the newly installed & configured "remote" VPN site. Thing is, either my Googling skills are pathethically horrible, or there doesn't seem to be much (or any, at all) information about how to configure an ISA Server 2000 for this purpose. Lots of stuff on 2004, of course; also, I think I saw something for 2006. But nothing I could find about 2000.

Reading about 2004, it seems that the only way I can do site-on-site with a Cisco router (read: a non-ISA-Server machine) is through something they call a "IPSec tunnel". Fair enough. However, I can't figure for the life of me how could I even start to find, leave alone configure, such a thing.

Do you, people, happen to know how to do IPSec tunelling on a ISA Server 2000, so I can connect to a Cisco WRV210 VPN-enabled router, and build a site-to-site VPN for both networks?

Or is this not possible at all? (Meaning I should change anything in this configuration to make it work...)