In the DNS Servers section, make the following changes:
Specify DNS servers in theDNS Serversedit boxes. You also have an option to select the gateway for each DNS server using the adjacentGatewaydrop-down box. If you want to add more than two DNS servers, click on theAdd DNS Serverbutton, and another edit box will appear.
Uncheck the Allow DNS server list to be overridden by DHCP/PPP on WAN checkbox.