Round-trip times to Active Directory server are taking more than 100 ms
Topic Last Modified: 2011-01-13
The Microsoft® Exchange Server Analyzer Tool queries the WIN32_PingStatus Microsoft Windows® Management Instrumentation (WMI) class in the root\cimv2 namespace to determine the value for the ResponseTime key. If the Exchange Server Analyzer finds the value for the ResponseTime key to be greater than 100 milliseconds (ms), an error is displayed.
The ResponseTime key represents the time elapsed (in milliseconds) to response to the Internet Control Message Protocol (ICMP) echo request (ping). Domain controllers used by an Exchange Server computer should always have a response time less than or equal to 10 ms. If the response time exceeds 100 ms, that could indicate performance or connectivity issues.
Check to ensure that the domain controller in question is not overloaded. Use the ADTest.exe tool to perform tests against the domain controller to see if the hardware can handle the anticipated load.
Check the event logs on the Exchange server and the domain controller to see if any network-related events have been logged that indicate one or more problems.
Use the DCDiag.exe and NetDiag.exe commands on the domain controller to verify correct configuration and health.
Finally, investigate the Active Directory® directory service site design. An Active Directory site is considered to be a network section that has high bandwidth and low latency. If the network is not partitioned according to this specification, consider partitioning the network into more Active Directory sites.
Note When the Analyzer tool runs the WMI query for the ping test, the default packet size and timeout values are overridden. Instead, the Analyzer uses a 4096 ICMP packet size (in place of the default 32 byte) and a 2000 ms timeout value (in place of the default 1000 ms).
Follow these steps to emulate the Analyzer's ping behavior manually.
Run the following command in the command line window of the Exchange server:
ping -L 4096 -N 6 <Active Server server name>
Note The command initiates six ping requests of 4096 bytes each.
For more information about the ADTest.exe tool, see the Active Directory Performance Testing Tool (ADTest.exe) Web site (http://go.microsoft.com/fwlink/?LinkId=33758).
For more information about the Win32_PingStatus WMI class, see the MSDN® article "Win32_PingStatus" (http://go.microsoft.com/fwlink/?LinkId=33549).
For more information about Active Directory site design, see "Designing the Site Topology" (http://go.microsoft.com/fwlink/?LinkId=33551).