ZyXEL Communications ZyWALL 300 User Manual

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Chapter 15 DDNS
ZyWALL USG 300 User’s Guide
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15.1.2  High Availability (HA)
The DDNS server maps a domain name to the IP address of one of the ZyWALL’s WAN ports. 
If that WAN port loses its connection, high availability allows the ZyWALL to substitute the 
HA port’s IP address in the domain name mapping.
15.1.3  Mail Exchanger
DynDNS can route e-mail for your domain name to a specified mail server. The server is 
called a mail exchanger. For example, if there is e-mail for 
john-doe@yourhost.dyndns.org
DynDNS routes the e-mail to the IP address you specify for the mail exchanger.
DynDNS can also provide an additional service, in which it holds onto your e-mail if your 
mail server is not available. Once your mail server is available again, the DynDNS server 
delivers the mail to you. This service is called backup.
Please see 
www.dyndns.org
 for more information about mail exchangers and backup.
15.2  DDNS Screens
Each domain name requires information about the DynDNS services and DynDNS account, as 
well as how the ZyWALL updates the IP address.
The DDNS Type indicates which DynDNS service you are using. The ZyWALL supports 
three services: dynamic DNS, static DNS, and custom DNS. Please see www.dyndns.org for 
more information about each of these services.
The ZyWALL needs to know the UsernamePassword, and Domain Name for your 
DynDNS account. You can also use the wildcard check box to indicate whether or not the 
wildcard feature should be supported.
You must also specify an IP Address Update Policy. This policy controls how the ZyWALL 
determines the IP address that is mapped to your domain name in the DDNS server. There are 
three policies: InterfaceAuto, and Custom.
• Interface - You specify which WAN Interface (WAN port’s IP address) to use for the 
domain name, and you can also specify an alternative HA Interface, in case the WAN 
interface is not available.
• Auto - The DDNS server checks the source IP address of the packets from the ZyWALL 
for the IP address to use for the domain name. You might consider this if there are one or 
more NAT routers between the ZyWALL and the DDNS server.
"
The ZyWALL may not determine the proper IP address if there is an HTTP 
proxy server between the ZyWALL and the DDNS server.
• Custom - If you have a static IP address, you can specify the Custom IP address to use 
for the domain name. The ZyWALL still sends the static IP address to the DDNS server.