The DNS is your routers ip address. the secondary DNS is 0.0.0.0 or thats what mine was
you can go to your routers
website and enter it manually. Type 192.168.1.1 this might be it or try 192.168.2.1 or 192.168.1.100
when it shows your routers info write it down and then put it in your xbox's network by entering it manually. btw the secondary DNS is just 0.0.0.0 if it doesn't give you two. the gateway
is just your routers ip address.
what else you can do is do port forwarding.
But the xbox is not a static ip address so it'll change. what you can do is when it says to put your ip address in your xbox put all the numbers the same as the routers ip address BUT DON'T USE THE SAME LAST NUMBER! so like if your routers ip address is 192.168.1.1 you can use 192.168.1.23 i use 192.168.2.15 but you may not have the 2 in yours. http://portforward.com/english/applications/port_forwarding/XboxLive360/XboxLive360index.htm
a website that'll helphttp://support.microsoft.com/kb/908874
list of ports you have to open
any other ?'s email
me at email@example.com