Step2) Dns - Planet Networking & Communication XRT-501 Quick Installation Manual

Step2) DNS

A Domain Name System (DNS) server is like an index of IP addresses and Web
addresses. If you type a Web address into your browser, such as www.router.com,
a DNS server will find that name in its index and the matching IP address. Most
ISPs provide a DNS server for speed and convenience. If your Service Provider
connects you to the Internet with dynamic IP settings, it is likely that the DNS
server IP address is provided automatically. However, if there is a DNS server that
you would rather use, you need to specify the IP address of that DNS server here.
Parameter
Automatic It will detect the DNS server automatically
This is the ISP's DNS server IP address that they gave you; or
Fixed
you can specify your own preferred DNS server IP address
Description
1