Recipe 12.12. Measuring Link Speed and Latency Between Two Hosts

Problem

You want to measure the link speed between two hosts.

Solution

Using a command-line interface

The Windows Server 2003 Resource Kit includes a new tool called linkspeed, which measures the connectivity between two hosts. You run the command from one system and target a remote system:

> linkspeed /s \\<ServerName> > linkspeed /s <ServerDNSName>

Alternatively, you can specify the /dc switch to have it test the system's current domain controller:

> linkspeed /dc

Discussion

Finding the link speed between two hosts is often useful when troubleshooting network connectivity problems. For example, if a client is having problems authenticating to Active Directory, you should find out the link speed between the client and the domain controller with which it is authenticating. A slow speed, perhaps due to congestion, could be the cause. If you want to determine the average link speed between two hosts, you should run the linkspeed command several times over multiple days. The results for any particular run of linkspeed could vary significantly depending on what is happening in the network at that time.