ZyXEL Communications EMG5324-D10A User Manual
EMG5324-D10A User’s Guide
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H A P T E R
11
DNS Route
11.1 Overview
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.
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 Device 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 Device receives a DNS reply from a DNS server, it
creates a new entry for the resolved IP address in the routing table.
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 Device 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 Device 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 ptm0.100 is
set to be the system DNS server. The DNS server 10.10.23.7 is obtained from the WAN interface
ppp1.123. You configure a DNS route for *example.com to have the Device forward DNS requests
for the domain name mail.example.com through the WAN interface ppp1.123 to the DNS server
10.10.23.7.
set to be the system DNS server. The DNS server 10.10.23.7 is obtained from the WAN interface
ppp1.123. You configure a DNS route for *example.com to have the Device forward DNS requests
for the domain name mail.example.com through the WAN interface ppp1.123 to the DNS server
10.10.23.7.
Figure 80
Example of DNS Routing Topology
WAN
LAN
ptm0.100
ppp1.123
DNS:10.10.23.7
DNS:168.92.5.1
sip.service.com
mail.example.com
(Default)