1.)     On Win XP desktop go to “Start “ and select “Run” then type cmd.

Another window will pop up on your screen.

2.)     Telnet to the router.

Type telnet  x.x.x.x (where x.x.x.x is the private IP of the router), then press enter  (as seen below).

3.)     Type the router password and press enter.

4.)     Type sys domainname  <wan1/wan2>  <Domain Name Suffix (max. 40 characters)> then press enter.

5.)     To check type sys domainname ?

6.)     Type exit to exit telnet.