Cisco VPN and Parallels over dial-up

Yes, I know, it doesn't get more convoluted than that.

So here's the story. I have a fairly new (December) MacBookPro, running 10.4.8. On it I have Parallels build 1970 and Cisco VPN 4.9.01 (0030).

While at work I use the VPN across wireless just fine. However, my traveling (not to mention my home) brings me to places where I need dial-up access. For that I use an external USB modem. Parallels connects through the USB modem just fine for normal surfing, but it does not get along with the VPN accross PPP.

What happens is that shortly after connecting to the VPN Parallels happily reminds the machine that it wants to use some addresses on 10.*.*.* to communicate with the Mac, and therefore the outside world. The VPN sees this, panics, and shuts down. If I turn off Parallels NAT and Parallels Host-Guest in the Network system preferences panel, I can use the VPN properly. Of course, the problem is that the only reason I have Parallels to begin with is because we have some Windows-only programs that I need to use across the network.

So, does anyone have any suggestions on how to either get Parallels to talk to the host OS without using a handful of extra IP addresses, or to fool Cisco into not seeing those addresses and giving up?

 

Anybody?

Well, I guess I really am the only person on earth with this weird setup.

 

You're not the only one.

Nope, you're not the only one. Using a verizon Wireless EVDO card gives the same behavior. have to disable Parallels interfaces and this just blows the whole idea of what I need to do. I haven't for other posts yet. Yours is the first I found that is similar.