Home > Articles > Microsoft > MCSE

This chapter is from the book

DHCP Server Management and Monitoring

Objective:

Manage DHCP.

  • Manage DHCP databases.

We have spent some time now examining the installation and configuration of the Windows Server 2003 DHCP service. The final piece of the DHCP puzzle is managing and monitoring the server after it is installed and configured. The Windows Server 2003 DHCP server bundles enhanced monitoring and statistical reporting for precisely that purpose.

The DHCP console has several features that can be accessed by selecting the server and clicking the Action menu or by right-clicking the server. We examine these management and monitoring features in more detail in the following sections.

Examining the DHCP Server Statistics

The Display Statistics command opens the Server Statistics window, which is shown in Figure 2.34.

Figure 2.34

Figure 2.34 The Server Statistics window quickly displays pertinent DHCP statistics.

The Server Statistics window displays the following statistics:

  • Start Time—The date and time the service was started.
  • Up Time—The total uptime for the DHCP service. If you restart the service, this number resets to zero, even if the DHCP server has not been restarted.
  • Discovers—The number of DHCPDISCOVER packets the server has received.
  • Offers—The number of DHCPOFFER packets the server has sent.
  • Requests—The number of DHCPREQUEST packets the server has received.
  • Acks—The number of DHCPACK packets the server has sent.
  • Nacks—The number of DHCPNACK packets the server has sent.
  • Declines—The number of DHCPDECLINE packets the server has received.
  • Releases—The number of DHCPRELEASE messages the server has received.
  • Total Scopes—The total number of scopes that are active on the server.
  • Total Addresses—The total number of addresses available. This number includes the number of addresses for all the active scopes on the server.
  • In Use—The number of addresses presently leased to DHCP client computers.
  • Available—The number of addresses available for lease for the total address pool.

DHCP Server Backup and Restore

As mentioned earlier in this chapter, DHCP server backup and restore is one of the new features found in the DHCP service in Windows Server 2003. Two types of backups from the DHCP console are supported:

  • Synchronous—A synchronous backup occurs automatically on the configured interval. The default interval is 60 minutes and can be changed from the registry location HKEY_LOCAL_MACHINE\SYSTEM\
    CurrentControlSet\Services\DHCPServer\Parameters\BackupInterval
    .
  • Asynchronous—An asynchronous backup is a manual backup that is performed by using the Backup command from within the DHCP console.

Both types of DHCP backups place their data in the same location, which is %systemroot%\System32\Dhcp\Backup by default. You can then use Windows Backup (NTBACKUP.exe) or any other backup application to safely back up this data to another location. You can change the database backup folder by selecting a different local folder during a manual backup or by changing the backup folder location in the DHCP server properties.

Backups of the DHCP data from the DHCP console include the following items:

  • All scopes
  • All reservations
  • All leases
  • All options, including server options, scope options, reservation options, and class options
  • All registry data in the following registry location: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DHCPServer\Parameters

You can manually perform a backup by selecting Action, Backup. In addition, you can perform the restoration of the DHCP data by selecting Action, Restore. If you want to change the backup path, you can do so from the Advanced tab of the DHCP Server Properties dialog box.

Reconciling the DHCP Database

Objective:

Troubleshoot DHCP.

  • Verify database integrity.

When you reconcile scopes on your DHCP server, you are comparing the information contained in the DHCP database against the information stored in the registry. Typically, reconciliation of scopes is performed when you are observing problems with the DHCP server and want to verify the configured addresses. The Reconcile All Scopes command allows you to perform this comparison should you need to. You can click the Verify button in the Reconcile All Scopes dialog box (shown in Figure 2.35) to check the consistency of the database and get a report of any errors.

Figure 2.35

Figure 2.35 You can reconcile all scopes from the Reconcile All Scopes dialog box.

Stopping the DHCP Server

Sometimes you'll want to prevent a DHCP server from giving out leases so that you can perform maintenance on the server or make configuration changes to scopes on the server. You can cause this happen by either unauthorizing the server or by stopping the DHCP server service. The Unauthorize command removes the DHCP server from the list of authorized DHCP servers in Active Directory. You are warned before removal occurs, as shown in Figure 2.36.

Figure 2.36

Figure 2.36 Unauthorizing a DHCP server prevents it from servicing client requests.

The advantage of unauthorizing a server versus stopping the DHCP server service, as shown in Figure 2.37, is that you can still perform scope and server configuration and modification while the server is unauthorized. That is not possible when the DHCP server service has been stopped on the server.

Figure 2.37

Figure 2.37 Stopping the DHCP server service removes the ability to perform configuration on it.

Configuring Options and Classes

The options Define User Classes, Define Vendor Classes, and Set Predefined Options are beyond the scope of Exam 70-291. You will probably not use them in the context of a standard DHCP installation, but you should be aware of what user classes and vendor classes are in general so that your knowledge of DHCP will be complete.

  • User classes—User classes are generally created for administrative purposes, similar to user groups. They can be used to identify all the DHCP clients in a specific department or location. User classes are used to assign DHCP options to groups of DHCP clients.
  • Vendor classes—Vendor classes are generally used to provide vendor-specific DHCP enhancements. For example, the Windows Server 2003 DHCP service has the capability to disable NetBT on its DHCP clients.

Changing the Server State

Should you want to change the state of the server, perhaps pause or stop the DHCP server altogether, you can do this from the Action menu. Selecting Action, All Tasks opens a submenu that allows you to control the operational state of the DHCP server. The following options are available:

  • Start—Starts the DHCP service. This option is available only if the service is stopped or paused.
  • Stop—Stops the DHCP service. This option is available when the service is running or paused. This option causes the server statistics to be reset.
  • Pause—Pauses the DHCP service. This option does not reset the statistics.
  • Resume—Resumes the DHCP service after it is paused. This option is available only when the service is paused.
  • Restart—Restarts the DHCP service, resetting the server statistics in the process. This option is available only if the service is currently running.

DHCP Server Common Commands

The three commands Delete, Refresh, and Export List are common ones. The Delete command deletes the DHCP server. The Refresh command causes all the displayed information to be refreshed with a current status. The Export List command allows you to export the information displayed in the right pane of the console window to a tab- or comma-delimited text or Unicode text file. You can export a list of various nodes by clicking them before selecting the Export List command.

The Properties command opens the Properties dialog box for the selected DHCP server. The Properties dialog box (shown previously in Figure 2.33) opens to the General tab, which allows you to configure the following options.

  • Automatically Update Statistics Every—This option allows you to set the automatic refresh of the statistics, as well as the interval at which the statistics are refreshed.
  • Enable DHCP Audit Logging—This option allows you to log all the DHCP activity to a text file located in the %systemroot%\System32\dhcp folder, which can be opened in Notepad or any other text editor. This is an excellent option to select if you are troubleshooting a DHCP problem and want to see what activity is taking place on the server.
  • Show the BOOTP Table Folder—This option deals with BOOTP backward compatibility and allows you to view the table that contains the BOOTP configuration entries. After you select this option, the BOOTP Table node appears in the DHCP console, as shown in Figure 2.38. From this node you can configure boot images for BOOTP clients. Remember, however, that you still need to provide your own third-party TFTP server.
Figure 2.38

Figure 2.38 When the BOOTP Table folder is enabled, you can perform configuration of BOOTP boot images.

The DNS tab of the Properties dialog box is discussed in detail earlier in this chapter, in the section "Configuring DHCP for DNS Integration." You can use the Advanced tab, shown in Figure 2.39, to perform more advanced and less common configuration tasks.

The Advanced tab has the following configuration options:

  • Conflict Detection Attempts—This option causes the DHCP server to check for conflicting IP addresses on the network before issuing an address. Although this sounds like a great way to make sure there are no address conflicts, it can add significant overhead to the server, and you should use it only while you're troubleshooting address conflict issues. By default, this option is set to 0.
  • Audit Log File Path—If audit logging is enabled, the log file is located in the %systemroot%\System32\dhcp directory. You can modify the location to be any location on the local computer (including mapped drives).
  • Database Path—This option allows you to specify the location of the DHCP database. By default, it is in the %systemroot%\System32\dhcp directory. You can modify the location to be any location on the local computer (including mapped drives).
    Figure 2.39

    Figure 2.39 The Advanced tab contains all the options that don't fit anywhere else.

  • Backup Path—This option allows you to specify the location of the DHCP backup file. By default, it is in the %systemroot%\System32\dhcp\backup directory. You can modify the location to be any location on the local computer (including mapped drives).
  • Change Server Connection Bindings—This option allows you to view the connections through which the DHCP server is providing addresses. If you have multiple network adapters in a DHCP server, you might want to configure DHCP for only selected interfaces. You can click the Bindings button to view and configure the binding on your computer, as shown in Figure 2.40.
    Figure 2.40

    Figure 2.40 You can view and change the DHCP bindings from the Bindings window.

  • DNS Dynamic Updates Registration Credentials—As discussed previously, this option allows you to specify a domain user account to be used during DNS dynamic updates.

Pearson IT Certification Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Pearson IT Certification and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Pearson IT Certification products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by Adobe Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.pearsonitcertification.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020