• Article

DNS servers for the specified domain are not responding

 

Topic Last Modified: 2007-11-16

The Microsoft Exchange Server 2007 Management Pack for Microsoft Operations Manager (MOM) monitors the Windows Application log on computers that are running Exchange Server 2007 and generates this alert when the event or events specified in the following Details table are logged.

To learn more about this event, do one or more of the following:

  • Review the description of the event that includes the variables specific to your environment. From the MOM Operator Console, select this alert, and then click the Properties tab.

  • Review all events that have been logged that meet the criteria of this MOM alert. From the MOM Operator Console, click the Events tab, and then double-click the event in the list for which you want to review the event description.

Details

Product Name

Exchange

Product Version

8.0 (Exchange Server 2007)

Event ID

2120

Event Source

MSExchange ADAccess

Alert Type

Warning

MOM Rule Path

Microsoft Exchange Server/Exchange 2007/Common Components/Active Directory Access

MOM Rule Name

DNS servers for the specified domain are not responding. Verify that the IP addresses of the DNS servers used by this computer are correct. Check domain controller health and network connectivity.

Explanation

This Warning event indicates that DNS servers for the specified domain are not responding. The domain controllers from the specified domain will not be used by DSAccess. As long as there is sufficient capacity in usable domain controllers in other domains, it will not cause mail flow interruption. But we recommend that you investigate the issue and fix it.

If the event contains the name of the local domain, topology discovery cannot be completed, and this will cause mail flow interruption.

This event may be logged when the following conditions occur:

  • The DNS servers did not respond because there is a connectivity problem.

  • There is no connectivity problem and the DNS servers are running. However, this computer could be using DHCP to obtain IP addresses for its DNS servers and the DHCP server could be providing incorrect IP addresses.

User Action

To resolve this event, do one or more of the following:

  • If this event is rarely seen, it can safely be ignored.

  • If this Warning event is logged at specific times or if any other pattern is detected, do the following:

    • Verify that the IP addresses of the DNS servers that are used by this computer are correct.

    • Determine whether DNS servers are running. To determine whether the DNS servers are running, you can use the DNS console in Microsoft Management Console (MMC) to view local and remote DNS servers.

    • Determine whether this computer uses DHCP to obtain its DNS server IP addresses by typing ipconfig /all at the command prompt. Then, if the DHCP Enabled setting is set to Yes, this computer uses DHCP to obtain DNS server addresses. Contact the network administrator to verify that the DHCP server is running and providing correct DNS server IP addresses.

    • Use the Ping or PathPing command-line tools to test basic connectivity. Use Ping to isolate network hardware problems and incompatible configurations. Use PathPing to detect packet loss over multiple-hop trips. For more information, see Microsoft Knowledge Base article 325487, How to troubleshoot network connectivity problems.

    • Run the Dcdiag command line tool to test domain controller health. To do this, run dcdiag /s:<Domain Controller Name> at a command prompt on the Exchange Server. Use the output of Dcdiag to discover the root cause of any failures or warnings that it reports. For more information, see Dcdiag Overview at the Microsoft Windows Server TechCenter.

For More Information

To search the Microsoft Knowledge Base articles based on criteria that generated this alert, visit the Search the Support Knowledge Base (KB) Web site.

To review Exchange 2007 event message articles that may not be represented by Exchange 2007 MOM alerts, see the Events and Errors Message Center.

If you are not already doing so, consider running the tools that Microsoft Exchange offers to help administrators analyze and troubleshoot their Exchange environment. These tools can help you make sure that your configuration is in line with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. Go to the Toolbox node of the Exchange Management Console to run these tools now. For more information about these tools, see Toolbox in the Exchange Server 2007 Help.