The Internet Layer
The Internet layer is the core layer of the TCP/IP protocol suite. This layer provides communication between network devices. The responsibility of this layer is to address, pack, and then route the data. The protocols contained in the Internet layer are:
IP: Routes data to the destination in the form of datagram (a group of packets consisting of data or information). Datagrams can be routed differently by following different paths. Also, this protocol does not keep track of the routes after the datagrams reach the destination.
Address Resolution Protocol (ARP): Converts IP addresses to Media Access Control (MAC) addresses or the physical address present on each device to establish communication between the devices that are connected in a network.
Reverse Address Resolution Protocol (RARP): Allows a computer to find its IP address when MAC address or physical address is known to it. This protocol is used when a computer connects to a network for the first time.
Internet Control Message Protocol (ICMP): Provides a base for Ping commands. This protocol is used by a computer or gateway to report datagram problems to the sender within the IP network.
Internet Group Management Protocol (IGMP): Helps in multicasting data to multiple recipients at the same time.