I do it all the time but mostly with Windows guests. You may have to use bridged NIC if you are using ipsec in your VPN. A lot of ipsec vpn devices/programs cannot handle multiple layers of NAT. Our SSL VPN box doesn't care.
I guess the question I am asking is this. Is there anything that I need to setup on the host Linux system to make the guest XP system be able to use a VPN connection to an external server. I am using a Cisco systems VPN client on my XP system. I seem to be able to establish a VPN connection with the Cisco client software but then no other programs are able to use the VPN connection.
I am not very familiar with all this networking stuff. How can I tell if I am connected to the external host system?
In one XP guest I run the Cisco VPN client (Version 7, I think) with a firewall in the guest - The firewall was very "tricky" to set up.
In another XP guest I run a Aventail VPN client with no firewall in the guest.
I run the guests under Ubuntu 8.04.1 LTS (Desktop) with absolutely no problems.
I run both guest vms with their respective VPN connections going simultaneously - I am in heaven :).
I did nothing special to the host setup.. As long as it's got an internet connection and I do run a NAT connection for each of the guests - originally I thought I might have to have a static IP for the Cisco guest, but my IT guy set up the cisco router so that it just works - very nice.
I am not familiar with the Cisco VPN but both of my VPN client programs pull an IP address from the subnet of the LAN I am VPNing to across the Internet. You should be able to see this in the result of: ipconfig/all in your XP guest system. That is what your other programs need to have to make it look like you are directly connected to the LAN across the Internet.
What can confuse some VPN connections is the use of the same subnet at both ends. Are you able to connect and use the VPN from your host system? If so, you might want to post the results of ipconfig/all from both the host and guest.
What is the subnet on the LAN at the other end?
You should make sure you are configured for bridged versus NAT on your guest.
Hey Gerry, I recently installed OpenVPN and it is working great for me. Aside from being a command line install its quite straight forward. I Basically installed it copied the keys to the appropriate locations and away it went. Only difference is that I am using running on esxi3.5 u2 and my host/guest are wk3ee/xp home. OpenVPN is available for basically all OS's though.
I use Cisco VPN from an XP VM on an XP host with bridged networking.