Recipe14.17.Viewing DHCP Utilization Statistics


Recipe 14.17. Viewing DHCP Utilization Statistics

Problem

You want to view statistics on the number of DHCP requests a particular server has processed.

Solution

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 You can get similar information by running the following command:

    > netsh dhcp server \\<ServerName> 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.

    Discussion

    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.

    Table 14-2 lists counters you can track in Performance Monitor. Most of these counters are rates (i.e., the number of transactions per second). If you want the overall number per transaction, open the Display Statistics dialog in the DHCP snap-in.

    Table 14-2. DHCP server performance monitor counters

    Counter name

    Counter description

    Acks/sec

    Rate of DHCP Acks sent by the DHCP server

    Active Queue Length

    Number of packets in the processing queue of the DHCP server

    Conflict Check Queue Length

    Number of packets in the DHCP server queue waiting on conflict detection (ping)

    Declines/sec

    Rate of DHCP Declines received by the DHCP server

    Discovers/sec

    Rate of DHCP Discovers received by the DHCP server

    Duplicates Dropped/sec

    Rate at which the DHCP server received duplicate packets

    Informs/sec

    Rate of DHCP Informs received by the DHCP server

    Milliseconds per packet (Avg)

    Average time per packet taken by the DHCP server to send a response

    Nacks/sec

    Rate of DHCP Nacks sent by the DHCP server

    Offers/sec

    Rate of DHCP Offers sent out by the DHCP server

    Packets Expired/sec

    Rate at which packets are expired in the DHCP server message queue

    Packets Received/sec

    Rate at which packets are received by the DHCP server

    Releases/sec

    Rate of DHCP Releases received by the DHCP server

    Requests/sec

    Rate of DHCP Requests received by the DHCP server


    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. For more on enabling DHCP auditing, see Recipe 14.12.

    See Also

    Recipe 14.12



Windows Server Cookbook
Windows Server Cookbook for Windows Server 2003 and Windows 2000
ISBN: 0596006330
EAN: 2147483647
Year: 2006
Pages: 380
Authors: Robbie Allen

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