ZyXEL Communications P-873HNU-51B, User Manual

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P-873HNU(P)-51B User’s Guide
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Dynamic DNS Setup
12.1 Overview
DNS
DNS (Domain Name System) is for mapping a domain name to its corresponding IP address and
vice versa. The DNS server is extremely important because without it, you must know the IP
address of a machine before you can access it.
In addition to the system DNS server(s), each WAN interface (service) is set to have its own static
or dynamic DNS server list. You can configure a DNS static route to forward DNS queries for certain
domain names through a specific WAN interface to its DNS server(s). The VDSL Router uses a
system DNS server (in the order you specify in the Broadband screen) to resolve domain names
that do not match any DNS routing entry. After the VDSL Router receives a DNS reply from a DNS
server, it creates a new entry for the resolved IP address in the routing table.
In the following example, the DNS server 168.92.5.1 obtained from the WAN interface eth10.0 is
set to be the system DNS server. The DNS server 10.10.23.7 is obtained from the WAN interface
VDSL_PoE/ppp0.1. You configure a DNS route for *example.com to have the VDSL Router forward
DNS requests for the domain name mail.example.com through the WAN interface VDSL_PoE/
ppp0.1 to the DNS server 10.10.23.7.
Figure 73
Example of DNS Routing Topology
WAN
LAN
eth10.0
VDSL_PPoE/ppp0.1
DNS:10.10.23.7
DNS:168.92.5.1
sip.service.com
mail.example.com
(Default)