The communications protocol of the public Internet, many wide area networks (WANs) and most local area networks (LANs). The Internet Protocol (IP) is part of the TCP/IP protocol suite, and the terms "IP network" and "TCP/IP network" are synonymous.
IP uses a packet-switched architecture, in which data are broken up into smaller "packets," with each packet containing a source address and destination address. IP packets are handed over to a data link layer protocol, such as Ethernet, for the actual, physical transmission to the next node in the network path.
IP is the Network Layer
While "IP" refers to the entire TCP/IP protocol suite, the term "IP layer" refers to just the network-to-network part, occupying layer 3 in the "protocol stack" (see below). To learn about IP networking, see OSI model
, TCP/IP abc's
, IP address
and IP on Everything
The TCP/IP "Stack"
The layer 3 Internet Protocol resides in the middle of the TCP/IP stack. It accepts packets from the upper layer TCP or UDP protocols and hands them to a lower layer data link protocol. Within a local network, the data link protocol is typically Ethernet. Within the public Internet, the data link protocols are SONET, ATM, frame relay and Carrier Ethernet.