How Client and Server Computers Update their DNS Names in Windows Server 2008 & Later Computers

In a windows networking environment, Domain Name System (DNS) client computers can use dynamic update to register with a DNS server. They can then dynamically update their resource records with a DNS server whenever there is a change in the configuration. For example, laptop clients can move around and there records may need to be updated.

On Windows Server 2003 and earlier versions the DHCP Client service, not the DNS Client service, was responsible for dynamically updating the DNS names. However, the behavior is different in Windows Server 2008 and later computers. On the newer systems, the DNS Client service, not the DHCP Client service, is responsible for dynamic updates.

In this article Understanding Dynamic Updates, Microsoft explains how dynamic updates work.

By default, computers that are statically configured for TCP/IP attempt to dynamically register host (A) resource records and pointer (PTR) resource records for IP addresses that are configured and used by their installed network connections. By default, all computers register records based on their fully qualified domain name (FQDN).

The primary full computer name, an FQDN, is based on the primary DNS suffix of a computer,appended to its computer name.

What prompts dynamic updates on clients? There could be several reasons, including the following.

– An IP address is added, removed, or modified in the TCP/IP properties configuration for any one of the installed network connections.

– An IP address lease changes or renews with the DHCP server any one of the installed network connections. For example, when the computer is started or if the ipconfig /renew command is used.

– The ipconfig /registerdns command is used to manually force a refresh of the client name registration in DNS.

– At startup time, when the computer is turned on.

– A member server is promoted to a domain controller.

The DNS Client service performs this function for all network connections on the computer, even if the connections are not configured to use DHCP. In other words, even if the network connections are configured with static IP addresses, the DNS Client service is responsible for performing dynamic updates.