4-Port ADSL Router User Manual

ONFIGURING

DNS

ERVER

DDRESSES

About DNS

Domain Name System (DNS) servers map the user-friendly

domain names that users type into their Web browsers (e.g.

yahoo.com) to the equivalent numerical IP addresses that

are used for Internet routing.

When a PC user types a domain name into a browser, the PC

must first send a request to a DNS server to obtain the equivalent

IP addresses. The DNS server will attempt to look up the domain

name in its own database, and will communicate with higher-level

DNS servers when the name cannot be found locally. When

the address is found, it is sent back to the requesting PC and is

referenced in IP packets for the remainder of the communication.

Assigning DNS Addresses

Multiple DNS addresses are useful to provide alternatives

when one of the servers is down or is encountering heavy traffic.

ISPs typically provide primary and secondary DNS addresses,

and may provide additional addresses. Your LAN PCs learn

these DNS addresses in one of the following ways:

•

Statically:

If your ISP provides you with their DNS server addresses,

you can assign them to each PC by modifying the PCs'

IP properties.