Each device accessing the Internet is supplied an IP address that designates the network it's connected to and the location. The IP address -- short for "Internet Protocol" -- is expressed as a series of numbers. According to the website What'sMyIPAddress.com, "IP addresses consist of four numbers separated by periods (also called a 'dotted-quad')." If your IP address is blocked by a website, there's little you can do to unblock it. Typically, IP addresses are blocked for violation of a website or company's policy. Abusive language on a message board may cause a website to block your IP address also.
Find out why your IP has been blocked. In most cases, you should be aware of a violation you've committed. The range of possibilities is vast, but it's generally for doing something illegal or something in violation of a website's rules. Rarely, an IP address can be blocked by accident.
Contact the website or company that has blocked your IP. Email them and ask for information on the ban if it hasn't already been provided.
Access your router by typing the IP address into you browser. Type "admin" for the user and password once the dialog box pops-up.
Scroll through the menu on your router. Find the "MAC address" tab.
Access the MAC Address and change one of the numbers. Save the new number. This should cause a new IP address to be assigned to your computer once you get on the Internet.
Changing the MAC address may not always force your ISP to grant you a different IP address.