P-661HNU Series Support Notes
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12. What is DDNS?
The Dynamic DNS service allows you to alias a dynamic IP address to a static
hostname, allowing your computer to be more easily accessed from various
locations on the Internet. To use the service, you must first apply an account
from several free Web servers such as http://www.dyndns.org/.
Without DDNS, we always tell the users to use the WAN IP of the
P-661HNU-Fx to reach our internal server. It is inconvenient for the users if this
IP is dynamic. With DDNS supported by the P-661HNU-Fx, you apply a DNS
name (e.g., www.zyxel.com.tw) for your server (e.g., Web server) from a
DDNS server. The outside users can always access the web server using the
www.zyxel.com.tw regardless of the WAN IP of the P-661HNU-Fx.
When the ISP assigns the P-661HNU-Fx a new IP, the P-661HNU-Fx updates
this IP to DDNS server so that the server can update its IP-to-DNS entry. Once
the IP-to-DNS table in the DDNS server is updated, the DNS name for your
web server (i.e., www.zyxel.com.tw) is still usable.
13. When do I need DDNS service?
When you want your internal server to be accessed by using DNS name rather
than using the dynamic IP address we can use the DDNS service. The DDNS
server allows to alias a dynamic IP address to a static hostname. Whenever
the ISP assigns you a new IP, the P-661HNU-Fx sends this IP to the DDNS
server for its updates.