# Dynamic DNS

Dynamic DNS (DDNS) is a mechanism that allows clients to dynamically update IP addresses for registered domain names. This is useful when an ISP uses PPP, DHCP, or XAuth to dynamically change the IP address for a CPE router (such as a NetScreen device) that protects a web server. Thus, any clients from the internet can access the web server using a domain name, even if the IP address of the CPE router previously changed dynamically. This is made possible by a DDNS server such as dyndns.org or ddo.jp, which contains the dynamically-changed addresses and their associated domain names. The CPE updates these DDNS servers with this information, periodically or in response to IP address changes.

This page allows you to initiate or delete the DDNS (Dynamic DNS) module entries in the DDNS Entries table. Each entry represents a module that allocates all resources needed for DDNS. Deleting an entry frees the resources.

Note: To see the DDNS table, you need to set either of the following options:

Config DDNS Client: Specifies the DNS has Dynamic DNS capability.

Enable DDNS Client: Enables DDNS functionality.

DDNS Entries Table

ID The Identification Number of the entry in the DDNS Entry table. This acceptable range for this value is 1-256.

Server Type The kind of DDNS server to use. You can choose between the ddo and dyndns server types.

Server Name The FQDN (Fully-Qualified Domain Name) of the DDNS server. The maximum length is 63 characters.

Username The Username of the DDNS account. The maximum length is 63 characters.

Interface The interface through which the device communicates with the DDNS server.

Next-Update The minimum period (expressed in minutes) between updates. The default is 10 minutes, and the allowable range is 1-1440.

Last-Response The status of the last response transmitted by the DDNS server (such as "NoChange", "Success", or "Error").

Configure Allows you to edit, refresh, or remove an entry in the DDNS Entries table.

To Configure a DDNS Client

Click New. For more information on configuring a new DDNS client, see Dynamic DNS Configuration.