I bought Parallels primarily so that I could VPN to work for after-hours support purposes. (The corporate VPN product, from Cisco, is steadfastly resistant to any Mac-native solution I can throw at it. Not even the Cisco client works for me.) My company won't provide any help to Mac users, either, so here I am--I really really need to have this work out. I gave it a shot last night in Win98 (latest version I have) but couldn't get it to connect. Is there some trick to set networking in order for this to work? I am hoping to upgrade to the newly-released 3.0, but still have (IIRC) 3188 currently. This depends on whether it is free for me or not, since I just bought Parallels like two weeks ago. If there were any networking issues, I hope they're ironed out now.
I took the Cisco VPN documentation supplied by my own corporate IT folks to Windoze users, and configured the Mac Cisco VPN client the same way. Worked a treat. No problems. Then I discovered Shimo http://www.nexumoja.org/projects/Shimo/. Even better. Let us know a little more, maybe we can help you: What kind of problems are you having getting your Cisco VPN client to connect? What version Cisco VPN client software do you have?
