This article was previously published under Q297795
We strongly recommend that all users upgrade to Microsoft Internet Information Services (IIS) version 7.0 running on Microsoft Windows Server 2008. IIS 7.0 significantly increases Web infrastructure security. For more information about IIS security-related topics, visit the following Microsoft Web site:
IMPORTANT: This article contains information about editing the metabase. Before you edit the metabase, verify that you have a backup copy that you can restore if a problem occurs. For information about how to do this, see the "Configuration Backup/Restore" Help topic in Microsoft Management Console (MMC).
WARNING: If you edit the metabase incorrectly, you can cause serious problems that may require you to reinstall any product that uses the metabase. Microsoft cannot guarantee that problems that result if you incorrectly edit the metabase can be solved. Edit the metabase at your own risk.
NOTE: Always back up the metabase before you edit it.
To enable reverse DNS lookup on IIS versions 4.0 and later, the EnableReverseDNS metabase entry must be set to TRUE.
When the EnableReverseDNS metabase entry is set to TRUE, the IP address of each Web client that connects to the IIS server is resolved to a DNS name, and the DNS name instead of the Web client IP address is placed in the IIS log files. Enabling reverse DNS also affects what CGI and ISAPI extensions see as a value of the RemoteHost variable.
For additional information about how to back up the registry, click the article number below to view the article in the Microsoft Knowledge Base: