User's Manual

23
DNS Configuration
Domain Name Service (DNS) is a service used on the Internet for resolving fully qualified domain
names (FQDN) to their Internal Protocol (IP) address. You can type the preferred DNS server IP
address, Alternative DNS server IP address that provided by ISP or automatically assigned by ISP.
Click submit and save settings to save your setting.
The DNS Configuration page allows users to set the configuration of DNS proxy.
The firmware supports the DNS proxy function. For the DHCP requests from local PCs, the DHCP
server will set the LAN port IP as the default DNS server. Thus, all DNS query messages will come
into LAN port first. The DNS proxy on the ADSL modem recorded the available DNS servers, and
forward DNS query messages to one of DNS server.
There are four DNS proxy modes available:
1. Disable DNS Proxy: The LAN port does not process the DNS query message. For the DHCP
requests from local PCs, the DHCP server will set the user-configured preferred DNS sever or
alternate DNS server whichever is available as the DNS server. Then all DNS query messages will
be directly sent to the DNS servers.
2. Use Auto Discovered DNS Servers Only: The DNS proxy will store the DNS server IP addresses
obtained from DHCP client or PPP into the table. And all DNS query messages will be sent to one
of the dynamically obtained DNS servers.
3. Use User Configured DNS Servers Only: The DNS proxy will use the user-configured preferred
DNS server and alternate DNS server. And all DNS query message will be sent to one of DNS
servers.
4. Auto Discovery + User Configured: The DNS proxy’s table has all the IP addresses of
dynamically obtained and user configured DNS servers.