The DNS search order is blank

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at]  

Topic Last Modified: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool queries the Win32_NetworkAdapterConfiguration Microsoft Windows® Management Instrumentation (WMI) class to determine whether a value is set for the DNSServerSearchOrder. If the value for this key on an Exchange server is blank, a warning is displayed.

This warning indicates that one or more of the network adapters on this computer do not have DNS IP addresses associated with them. Therefore, when this computer tries to connect to another computer, it is broadcasting across the local network for IP addresses. Therefore, name resolution will be slow, which may slow Exchange.

It is recommended that an IP address of at least one valid DNS server be entered. If you have more than one adapter on the computer, verify that all adapters have at least one valid DNS server IP address.

To set the DNS IP address on a network adapter

  1. In Network Connections, right-click the appropriate Local Area Network adapter, and then click Properties.

  2. On the General tab, double-click Internet Protocol (TCP/IP).

  3. On the General tab of the Internet Protocol (TCP/IP) page, enter at least one IP address of a valid DNS server, and then click OK.

For more information about configuring DNS to work with Exchange, see the Microsoft Knowledge Base article 322856, "How to configure DNS for use with Exchange Server" (