The primary DNS server cannot be contacted

[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: 2006-06-05

Microsoft® Exchange Server 2007 setup cannot continue because communication with the primary Domain Name System (DNS) server cannot be established.

Exchange 2007 setup requires that the local computer communicate with the authoritative DNS database for the domain.

Microsoft Exchange depends on DNS to resolve the IP Address of its next internal or external destination server.

Communication with the primary DNS server can fail for the following reasons:

  • The local TCP/IP configuration does not point to the correct DNS server.

  • The DNS server is down or unreachable because of a network failure or other reasons.

To resolve this issue:

  • Verify that the local TCP/IP configuration points to the correct DNS server.

To verify the local TCP/IP configuration

  1. Review the local TCP/IP configuration:

    For more information, see "Configure TCP/IP to use DNS" (

  • Verify that the DNS server is running and can be contacted.

To verify that the DNS server is running and can be contacted

  1. Verify that the DNS server is running by doing one or more of the following checks:

    • Look at the DNS server status from the DNS Administration program on the DNS server.

    • Restart the DNS server.

      For more information, see "Start, stop, pause, or restart a DNS server" (

    • Verify the DNS server responsiveness by using the nslookup command.

      For more information, see the instructions in "Verify DNS server responsiveness using the nslookup command" (