NETGEAR UTM5 Reference Manual page 86

If your network has a permanently assigned IP address, you can register a domain name and
have that name linked with your IP address by public Domain Name Servers (DNS).
However, if your Internet account uses a dynamically assigned IP address, you will not know
in advance what your IP address will be, and the address can change frequently—hence, the
need for a commercial DDNS service, which allows you to register an extension to its
domain, and restores DNS requests for the resulting fully qualified domain name (FQDN) to
your frequently changing IP address.
After you have configured your account information on the UTM, when your ISP-assigned IP
address changes, your UTM automatically contacts your DDNS service provider, logs in to
your account, and registers your new IP address.
Consider the following:
• For auto-rollover mode, you need an FQDN to implement features such as exposed hosts
and virtual private networks regardless of whether you have a fixed or dynamic IP
address.
• For load balancing mode, you might still need an FQDN either for convenience or if you
have a dynamic IP address.
Note: If your ISP assigns a private WAN IP address such as 192.168.x.x or
10.x.x.x, the DDNS service does not work because private
addresses are not routed on the Internet.

To configure DDNS:
1. Select Network Config > Dynamic DNS. The Dynamic DNS screen displays (see the
following figure).
The WAN Mode section onscreen reports the currently configured WAN mode (for
example, Single Port WAN1, Load Balancing, or Auto Rollover). Only those options that
match the configured WAN mode are accessible onscreen.
2. Click the submenu tab for your DDNS service provider:
• Dynamic DNS for DynDNS.org (which is shown in the following figure)
• DNS TZO for TZO.com
• DNS Oray for Oray.net
• 3322 DDNS for 3322.org
ProSecure Unified Threat Management (UTM) Appliance
Manually Configuring Internet and WAN Settings
86