Board Thread:General Discussion/@comment-72.171.192.249-20130215233545/@comment-65.92.180.137-20130216055942

It's your ISP, which assigns a dynamic IP address to your account. If you're using a dial-up internet account, it will change whenever to log on. If you're using an always on account, it will chang whenever you reset your modem, or when the ISP chooses.