If you are using the rogers gateway, as a gateway, there is nothing you need to do if you are getting an address automaticaly (via DHCP).
If you are using the gateway, but using a static address.. and want to just use the default rogers ones, you can just enter in the gateway's address (192.168.0.1 or whatever it may be)
If you are in bridged mode, using the gateway as just a modem.. and your own router.. if it is NOT pulling it automatically.. you can enter the following.
64.71.255.204
64.71.255.198
Alternatively... you can also use a DIFFERENT DNS, and not the rogers ones, if you so chose.
Say like google
8.8.8.8
8.8.4.4