I was working the other day as tech support for Internet and this guy couldn't connect to the Internet. He was using a 2-Wire router, the DSL light is on and the Internet light is off. I was thinking that he probably just need to set the router by choosing the connection type to be PPPoE (our service) and put his user name and password. This turns out to be a correct assessment and after helping him do that, he was connected.
However, along the way, I told him to open his LAN and check his default gateway and it was written 172.16.0.1. I told him to enter this in his browser and it entered into the configuration of his router.
My question is why didn't his default gateway start with 192.168? I thought local IP addresses have to start with that.