DHCP, Task: Compliance check-maintain dynamic update configuration

Task: Compliance check - maintain dynamic update configuration

Purpose

This task reviews the DHCP dynamic domain name system (DDNS) dynamic update settings to make sure that after a month of daily operations, the configuration still matches the original architectural intent given the configuration of the environment.

Windows Server 2003 DHCP services perform dynamic updates for DHCP clients based on how clients request that updates be done. This setting provides the best use of the DHCP service to perform the following dynamic updates on behalf of its clients:

● Client computers running Windows 2000 explicitly request that the DHCP service only update pointer (PTR) resource records used in DNS for the reverse lookup and resolution of the client's IP address to its name. These clients update their address (A) resource records for themselves.

● Clients running earlier Windows versions cannot make explicit requests for dynamic update preference. For these clients, the DHCP service can be configured to update both the PTR and the A resource records for the client.

Procedure 1: Check current dynamic update configuration via GUI

1. Start the DHCP management console by clicking Start, then Run, entering dhcpmgmt.msc and clicking OK.
2. If the appropriate DHCP server is not listed in the tree view on the left:

   a. Right-click DHCP (the first item), and select Add Server.

   b. Enter the hostname for the appropriate DHCP server or select from the authorized list, and click OK.

3. Double-click the appropriate DHCP server on the tree view in the left pane.
4. Click [+] to expand Superscopes (if any) and select the scope to check Dynamic Update configuration.
5. Right-click the scope and select Properties.
6. Click the DNS tab and verify the configuration.

Procedure 2: Modify dynamic update configuration

If legacy DHCP clients no longer exist in the environment, the architecture may prescribe that the configuration revert back to the original defaults for the DHCP server:

To enable DNS dynamic updates

1. Dynamically update DNS A and PTR records only if requested by DHCP clients.
2. Discard A and PTR records when lease is deleted.

Conversely, if the architecture dictates specific name resolution requirements and Windows NT® Server 4.0 servers are introduced, there may be a need to enable “Dynamically update DNS A and PTR records for DHCP clients that do not request updates.” These changes must be initiated and approved through the appropriate change management process.

Dependencies

None

Technology Required

Base DHCP Windows Server 2003