i wrote this article on dns aging/scavenging simplified awhile back. one of my coworkers recently asked me what the default refresh period was. wow, i had totally forgotten since i had written it and since i had forgotten to put it in the original post, it was more time on google than i wanted to spend to find it. that means – blog it. so here it is… the default refresh periods.
you can find this information from this article: http://technet.microsoft.com/en-us/library/cc757041.aspx.
|service||default refresh period|
|net logon||24 hours|
|dhcp client|| |
The DHCP Client service sends dynamic updates for the DNS records. This includes both computers that obtain a leased Internet Protocol (IP) address by using Dynamic Host Configuration Protocol (DHCP) and computers that are configured statically for TCP/IP.
|dhcp server|| |
Four days (half of the lease interval, which is eight days by default).
Refresh attempts are made only by DHCP servers that are configured to perform DNS dynamic updates on behalf of their clients, for example, Windows 2000 Server DHCP servers and Windows Server 2003 DHCP servers. The period is based on the frequency in which DHCP clients renew their IP address leases with the server. Typically, this occurs when 50 percent of the scope lease time has elapsed. If the DNS default scope lease duration of eight days is used, the maximum refresh period for records that are updated by DHCP servers on behalf of clients is four days.
and while i’m at it, if you wanted to change some of these defaults, you can do this by group policy as of windows 2003. i guess that should be pretty old news by now. here’s the link for that article: http://support.microsoft.com/default.aspx/kb/294785.