DGFV338 ProSafe Wireless ADSL Modem VPN Firewall Router Reference Manual
Basic Installation and Configuration 2-17
v1.0, April 2007
The default time to roll over after the primary WAN interface fails is 2 minutes (e.g., a 30-
second minimum test period, times a minimum of four tests).
Configuring Dynamic DNS (If Needed)
If your network has a permanently assigned (static or fixed) 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. In this case, you can
use a commercial dynamic DNS service, which allows you to register an extension to its domain,
and resolves DNS requests for the resulting FQDN to your frequently-changing IP address.
For rollover mode, you will need a fully qualified domain name (FQDN) to implement features
such as exposed hosts and virtual private networks regardless of whether you have a fixed or
dynamic IP address.
The gateway conta in s a clie n t that ca n co nnect to a dynamic DNS service provider. To use this
feature, you must select a service provider and obtain an account with them. After you have
configured your acco unt information in the gateway, whenever your ISP-assigned IP address
changes, your gateway will automatically contact your dynamic DNS service provider, log in to
your account, and register your new IP address.
Note: If your ISP assigns a private WAN IP address such as 192.168.x.x or 10.x.x.x, the
dynamic DNS service will not work because private addresses will not be routed
on the Internet.