Microsoft KB Archive/888849

Knowledge Base

Supplemental information to the "Using Microsoft Loopback Adapter" topic of the Microsoft Virtual Server 2005 Administrator's Guide

Article ID: 888849

Article Last Modified on 11/2/2007

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APPLIES TO

• Microsoft Virtual Server 2005 Standard Edition

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INTRODUCTION

This article offers supplemental information to the "Using Microsoft Loopback Adapter" topic of the Microsoft Virtual Server 2005 Administrator's Guide. The topic discusses how to configure the Internet Connection Firewall (ICF) feature and the Internet Connection Sharing feature on the host computer so that the host operating system can share its Internet connection. This configuration provides a protective boundary between the virtual network that uses the Microsoft Loopback adapter and external computers. This article includes additional information that will help you complete this task.

MORE INFORMATION

The following list provides information that will help you when you try to configure a virtual network to use the Microsoft Loopback adapter:

• When you configure Internet Connection Sharing on the physical network adapter where ICF is enabled, configure Connection Sharing so that the network adapter shares the Internet-connected connection with the Loopback adapter. To do this, click the Internet-connected connection in the Home networking connection list.
  

Note To access the Internet Connection Sharing settings, click Start, click Run, type ncpa.cpl, and then click OK. Right-click the physical network adapter, click Properties, and then click the Advanced tab.

• Turn off ICF for the Loopback adapter on the host computer. To do this, follow these steps:
  1. Click Start, click Run, type ncpa.cpl, and then click OK.
  2. Right-click the Loopback adapter, and then click Properties.
  3. Click the Advanced tab.
  4. If it is selected, click to clear the Protect my computer and network by limiting or preventing access to this computer from the Internet check box, and then click OK.
  5. Click Yes when you are prompted to confirm that you want to turn ICF off.
• Virtual networks that use the Loopback adapter must use the 192.168.0.x subnet because that is the network that Internet Connection Sharing will share out. If you are already using this network range for your local network, you must change the IP addresses on all devices to a different network range. This includes the internal address of your cable modem or router. If you use static Internet Protocol (IP) addresses on the guest virtual machines, you must set the default gateway to 192.168.0.1. For the Domain Name System (DNS) server address, you can use either the 192.168.0.1 address or use the same DNS server address that is specified on the host computer.
• Do not use a virtual Dynamic Host Configuration Protocol (DHCP) server. Internet Connection Sharing will allocate IP addresses.
• On the guest virtual machines, do not specify any Internet proxy servers in your Web browser.
• On the host computer, order your network adapters so that the "real" physical adapter is listed first. Otherwise, all Web pages may load slowly. To order your network adapters, follow these steps:
  1. Click Start, click Run, type ncpa.cpl, and then click OK.
  2. On the Advanced menu, click Advanced Settings.
  3. In the Connections box on the Adapters and Bindings tab, click the network adapter that you want to move, and then click the up or down arrow to reorder the network adapters.
  4. When you are finished, click OK.
• For Virtual Machine Remote Control (VMRC), add the host computer name to Microsoft Internet Explorer's "Trusted sites" and "Local intranet" Web content zones. To do this, follow these steps:
  1. Start Internet Explorer.
  2. On the Tools menu, click Internet Options.
  3. Click the Security tab.
  4. Click the zone that you want to add the host computer name to, and then click Sites.
  5. In the Add this Web site to the zone box, type http://host_computer_name, click Add, and then click Close.
     

Note For host_computer_name, substitute the network basic input/output system (NetBIOS) or the fully qualified domain name (FQDN) of the host computer. Use the name format that you use in VMRC to connect to the host computer.

• 1. Click OK.
• If you change the Loopback adapter TCP/IP settings on the host computer, restart the Virtual Server service. Otherwise, connectivity is not restored to guest virtual machines. To do this, follow these steps:
  1. Click Start, click Run, type services.msc, and then click OK.
  2. Right-click Virtual Server, and then click Restart.

MORE INFORMATION

For additional information about how to configure Internet Connection Sharing, click the following article number to view the article in the Microsoft Knowledge Base:

306126 How to configure Internet Connection Sharing in Windows XP

For additional information about the Internet Connection Firewall feature, click the following article numbers to view the articles in the Microsoft Knowledge Base:

283673 How to enable or disable Internet Connection Firewall in Windows XP

320855 Description of the Windows XP Internet Connection Firewall

Keywords: kbhowto kbinfo kbnetwork KB888849

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