How to connect the virtual networks of vmware guests running on different hosts?

In a test setup, we are running several virtual machines on a single vmware workstation host. All virtual machines are connected via a "host only" network. This runs fine up to 2 or 3 virtual machines (depending on the host hardware). To allow more virtual machines, we want to use more host machines.

Details about the environment and applications:

• Host PCs are running Windows XP in a corporate intranet.
• VMware used is Workstation 6.5
• Guests are running Windows Server 2003
• All guests act as Web Servers
• One of the guests additionally acts as Windows File server, offering shared folders for the other guests to connect to.

Restrictions:

• VMware guests shall not be visible from the intranet.
• Changes to the host PC are restricted by corporate policy.
• In the virtual network, no domain controller exists. All virtual machines are member of the same workgroup.
• Running the virtual network as NAT is possible. Port forwarding might be used if it does not conflict with ports used by the host PC.

Looking for a solution, I found hints about using router or vpn software on the hosts, but without any details how to setup.

(I found a similar question Sharing the network between 2 VMware hosts, but the answer was not sufficient for me.)

From serverfault gyrolf

• The VPN sounds like a good idea, but there is a certain degree of difficulty involved with setting up VPNs, and also involves "changes to the host pc" which would be "restricted by corporate policy."

  Have you thought about an ad-hoc wireless network? Maybe pick up a couple usb wifi adapters and set up a wireless network between the hosts.

  Also, you'll have to switch the networks for your VMs from host only to bridged, as host only won't communicate outside of the host.

  From JakeRobinson