CCBot/2.0 (http://commoncrawl.org/faq/)

Every computer connected to the Internet must have a unique number, an IP address. By convention, the IP address is saved by 4 numbers from 0 to 255, each separated by dots. Depending on the type of contract with our Internet Service Provider, we can always have the same IP address (static IP) or alternating, randomly selected from a pool of addresses reserved for our supplier.