Java™ Network Programming and Distributed Computing

3.2. Internet Protocol Addresses

Devices having a direct Internet connection are allocated a unique identifier known as an IP address. IP addresses may be static (in that they are bound permanently to a certain machine or device), or dynamic (leased to a particular machine or device for a certain period, for example in the case of an Internet service provider [ISP] that offers a pool of modems for dial-up connections). Dynamically assigned IP addresses are typically used when many devices require Internet access for limited periods of time. Thus addresses can be allocated from a pool of remaining addresses on a case-by-case basis. However, an IP address can be bound to a single machine only; it cannot be shared concurrently. This address is used ...