Using a VPN from the guest OS in Parallels

Problem statement: I am running OS X 10.6 (Snow Leopard), and have a Windows 7 virtual machine running under Parallels 5. I want to have both of them connected to a remote VPN at the same time. Getting the host Mac to connect to the VPN was not a problem. But connecting to the VPN from the Windows 7 guest would not work. It would just sit there at the “Verifying user name and password…” message.”

Solution:

  1. Set the virtual machine instance to use Bridged Networking (Default Adapter) instead of Shared Networking.
  2. Make sure that the advanced options for the VPN in the host OS X are not set to send all traffic over the VPN connection. (This is actually the default setting, but if you’ve just spent an hour fucking around with your network configuration trying to make it work, you may very well have changed this.)

This now allows me to connect the VPN on the host and the guest completely independently. (Either one or the other, or both at the same time.) I have no idea if this is a universal solution; if it doesn’t work for you, asking me why really isn’t going to help.