Viewing DHCP Utilization Statistics

Any time you look at the performance statistics, you need an understanding of the baseline performance. For example, if you look at the number of DHCP acknowledgments per second and find that your server is currently at 7, how do you know if that is more or less than normal? You really need to become familiar with how much traffic your server is getting so that if you suspect your server is becoming overloaded, you have a frame of reference.

Also, with DHCP the time of day is important. When users arrive in the morning and fire up their computers, there will be a lot of DHCP Discover requests by client computers. Depending on your lease duration, you may see additional spikes throughout the day. For example, if your lease duration is set to four hours, clients will begin to extend the lease after two hours. Then at the end of the day, when your users shut down their computers, you may see a lot of DHCP Release request activity.

For good rules of thumb concerning what to watch for when observing the DHCP performance counters, go to http://msdn.microsoft.com and search on “DHCP Server Object.” In the Performance Monitor Reference, Microsoft describes all of the counters and provides guidance on how to determine bottlenecks based on what you are seeing.

If you determine that you are seeing an unusually high rate of DHCP requests, you’ll want to learn what clients are generating the bulk of the traffic.

You can view a snapshot of the number of DHCP requests a server has processed by doing the following:

  1. Open the DHCP snap-in.
  2. In the left pane, right-click on DHCP and select Add Server.
  3. Type in the name of the DHCP Server you want to target and click OK.
  4. Right-click the server and select Action > Display Statistics.

You can get similar information by running the following command:

> netsh dhcp server \\ show mibinfo

You can also trend DHCP statistics over a period of time using Performance Monitor:

  1. Open the Performance Monitor snap-in.
  2. Click the plus (add) button in the right pane.
  3. Under Performance object, select DHCP Server.
  4. Under Select counters from list, click on a counter you want to view and click the Add button. You can also click on the Explain button to view more information about a specific counter.
  5. Click Close when you are done.