How to get your host talking with your Virtual Machine with Virtual Server 2005 R2

I wrote a guide on how to set up your Virtual Server 2005 environment, so that your VM can talk with your host.

This is a very generic requirement, often needed by developers working with server products such as SharePoint.

Virtual Server Network Settings
Matthew Cosier

Change Log
Friday, April 28, 2006
Friday, May 19, 2006
Monday, May 22, 2006
Tuesday, May 23, 2006

Setting up a loopback adapter

Navigate to control panel
Click add hardware
Click Next
Click “Yes, I have already connected the hardware”
Scroll down and choose “Add new hardware device”
Choose “Install the hardware that I manually select from a list (Advanced)
Choose “Network Adapters” then click Next
From the list on the left, choose “Microsoft”
From the list on the right choose “Microsoft Loopback Adapter”
Click Next
Click Next
Click Finish

Configuring Internet Connection Sharing

With the “Network Connections” window still open, right click your primary network adapter (typically “Local Area Connection” (for Cable/Ethernet) or “Wireless Network Connection” if you are using WiFi for your external internet access) and select ‘Properties”
Click the “Advanced” tab from within the properties dialog
Check the “Allow other network users to connect through this computer’s Internet Connection” check box
Note that if you have more than one adapter on your machine – it will ask you to choose the one that connects internally to your LAN, and will assume the current adapter you are changing settings on is the one which connects to the internet. This is so that you can share your internet connection in a LAN environment – either by Ethernet, or some other medium such as a PAN enabled Bluetooth connection. In this situation, choose your Loopback adapter from the list. By doing this, you are telling ICS that you intend on sharing the internet connection of your primary adapter with those who are connected to you through your loopback adapter.
Click OK

This will enable ICS, and start a local windows DHCP server on the 192.168.0.* subnet which your VM will use to renew an IP address. Your Loopback adapter should no longer say “Limited Connectivity”, as the host will automatically assign a static IP of 192.168.0.1 to the adapter, which is subsequently on the same subnet as the ICS DHCP server.

Important Note:
If you are sharing your internet connection to any other adapter other than your local loopback adapter (i.e., a connection is shared to another physical adapter or medium, such as your corporate LAN (this includes not explicitly choosing the loopback adapter from the list in 3 a – if you select to provide to only your loopback adapter, this should be irrelevant and shouldn’t cause you any problems)) and the network you are sharing to is living happily on the 192.168.0.* subnet, then you are going to have conflict issues. You will essentially be introducing a DHCP server on the LAN which will have the potential to override that of the main corporate DHCP server.

By default, ICS DHCP server will run on the 192.168.0.* subnet, and if your LAN is running on the same subnet, all of the clients on that network are potentially at risk of indecently renewing an IP address from your ICS host, instead of their intended corporate LAN DHCP server – giving them access to your shared internet connection, but losing all connectivity inside the corporate network.

Unfortunately, if you wish to introduce an ICS host on a network running on the 192.168.0.* subnet, you are going to have issues. The only way around it, is to change your LAN so that it will run on a different subnet. To do this, you will need to consult your LAN administrator, or your router configuration documents, to learn how to get your router to provide IPs on a different range. A good suggestion is to have your LAN use the 192.168.2.* range. This unfortunate problem will occur on most default home networks, as most routers will assume the default subnet of 192.168.0.*

Configuring your Virtual Server

Open your Virtual Server Administration Web Site
Click the Create button under the “Virtual Networks” menu
Type “LoopBack” for the virtual network name
Select “Microsoft Loopback Adapter” from the drop down list
Check the ‘connected’ check box, next to your virtual machine name, so that it will automatically configure your VM to use this connection.
Click OK

Note: To add a new network adapter (rather than changing the one that is already there) your virtual machine must not be in a running state.

Obtaining your Virtual Machine’s network address

Turn on your Virtual Machine
Within your virtual machine, open a command prompt by clicking Start->Run->cmd.exe then click OK
Type ipconfig
Under the Local Area Connection adapter, your IP address will be displayed. Note this address, as it is the address that will be used to connect locally to your virtual machine from your host
Open internet explorer to check that you now have an internet connection from within side your VM

Alternatively

Your VM has obtained its IP address through the local DHCP server on your host. In step 4, you will also have noticed the Connection-specific DNS Suffix was set to mshome.net. This is the default suffix that is used by ICS DHCP server. You can access your VM by taking advantage of domain name resolution by using %VMsMachineName%.mshome.net on your host.

Accessing your VM from the host

You will now have access to the virtual machine on the host via the IP retrieved in step 4, or the DNS name discussed above. To access the machine from the host:
1. Click start -> run -> cmd.exe and click OK
2. Type \\%ip-dns%\c$
a. Note, replace %ip-dns% with the IP retrieved from step 4, or your VM’s machine name .mshome.net

You can now map network drives to that address, and create TCP port forwarding on the host if need be.

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