Hey eZ-MONEY-Harley,
This is due to more than one console trying to share the same network port connection when trying to connect to a server. The only way around this would be to put one of the consoles in the router's DMZ. You would only be able to have up to two consoles play online at the same time this way. For more information on how to put your console in the router's DMZ, please consult your router documentation. If you are still unable to play online after setting up DMZ, let us know!
^MC