It is because of your ISP. There are a variety of ways that providers may manage the available IP addresses they have depending on how their network is setup and the type of connection you have. The ISP can explain more details about how this applies to you. But in general, their systems keep a pool of available IP addresses and force addresses leases to expire periodically so that their available pool of addresses doesn't become exhausted for people that aren't using them anymore.
Or, if you have a wireless modem, type your IP adress into a browser window and you can change the settings from a variable IP to a secure a constant IP adress.
However, unless you are a business and need a static IP address, I would not worry too much about IP.
Answered by
mteodor
at
Nov 18, 2010 11:55 AM