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

networkingvmware-workstationwindows-server-2003windows-xp

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.)

Best Answer

A "host only" network is exactly that: it only exists within a given host, and it can't have any communication with anything else; just think of it as connecting your VMs to a little desktop switch which does not have any other connection.

If you want those VMs to be able to talk with anything at all, you'll need to switch to "bridged" or "NAT" networks. With NAT, they'll be masked by the host's real IP address, thus, unless you set up some kind of VPN between the hosts, they will only be able to talk with your LAN, but not between VMs running on different hosts.

The simplest solution would be using a "bridged" network: this will behave like your VMs where actually connected to your real LAN, thus they'll be able to freely talk with anything else on the network, including other VMs running on different hosts; however, this will require them to actually access your LAN, so you may run into difficulties with your networking team (and you will of course need LAN IP addresses for them).