How do I connect specific network interfaces between multiple virtual machines?

Discussion in 'General Questions' started by lukeintas, May 11, 2007.

  1. lukeintas

    lukeintas Bit poster


    I have a university assignment to do, for which I am hoping to use Parallels. I can't work out if it can do what I want though, or if it can, how to do it.

    The assignment is a networking problem. It involves setting up network services on a small network (3 computers). To achieve this on a single PC (Mac in my case) the lecturer has suggested running three virtual machine instances.

    The problem is that one machine is to be configured as a server, one as a router, and the third as a client (the router machine is to have two network interfaces). Although setting up the three machines seems fairly straight forward, how do I connect the network interface of the virtual server to the first network interface of the virtual router and then connect the second network interface of the virtual router to the network interface of the virtual client?

    If anyone has any ideas they would be much appreciated.


  2. Hugh Watkins

    Hugh Watkins Forum Maven

    I'm not an expert

    but any network relies on IP numbers matching each other

    but I use automatic configuratikon whenever I can

    Hugh W
  3. lukeintas

    lukeintas Bit poster

    I'm thinking I can simply set the server and client virtual machines up on different subnets, and then put each one of the network interfaces of the router onto the respective subnets for the desired connections. This is what I'm going to try anyway. The initial instructions given by the lecturer use QEMU instead of Parallels, and talk about setting up socket connections to create the virtual network connections, before getting to the stage of subnetting.
  4. mmischke

    mmischke Hunter

    I'd probably use 10.x.y.z addressing (w/the default subnet mask of on one LAN and 192.168.x.y addressing (w/the default subnet mask of on the other, just to keep things simple. You could certainly accomplish the same thing using any class A, B or C range and some crafty subnetting, but in my mind, that would seem trickier to debug.

    As for QEMU, it's a neat piece of work, but it's an emulator, not a virtualizer, meaning it's a lot slower than Parallels. It's also tougher to configure.
  5. lukeintas

    lukeintas Bit poster

    Setting up "host only" networking and different subnets has done the job. I now have:

    Win2K Client --- FreeBSD Router --- Fedora Core 1 Server

    I set the IP addresses of the two network interfaces on the router machine to and respectively. The client machine has a IP address of and the server has an IP address of (with all interfaces having a subnet mask of

    Of course, to enable connectivity between the client and the server I had to enable packet forwarding on the router machine. This was one of the actual assignment tasks though.

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