ARP — Address Resolution Protocol

ARP — Address Resolution Protocol
The Address Resolution Protocol (ARP) is a communication protocol used for discovering the link layer address (e.g. MAC address) that is associated with a given internet layer address, commonly IPv4.
The mapping function provided by ARP is critical to the Internet protocol suite and has been implemented with many combinations of network and data link layer technologies, such as IPv4, Chaosnet and DECnet using IEEE 802 standards, FDDI, X.25 and Frame Relay amongst others.
- ARP was defined in 1982 by RFC 826 (Internet Standard STD 37).
- In IPv6 networks, the ARP mapping functionality is provided by the Neighbor Discovery Protocol (NDP).
- ARP sends request-response messages encapsulated in a link layer protocol, not allowing to route data across internetworking nodes. This means the boundaries of ARP are within the individual network, which places ARP into the link layer of the IP suite.
Packet Structure
The message format of Address Resolution Protocol simply contains one address resolution request or response. The message size depends on the sizes of the link and network layer addresses. The message header specifies the active network type and address size of each layer and contains an operation code for request (1) and reply (2). The payload of the packet consists of four addresses: the hardware and protocol address of the sender and the receiver hosts.

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IP Protocols
- ARP — Address Resolution Protocol
- FTP — File Transfer Protocol
- HTTP
- IP Routing
- TCP — Transmission Control Protocol
The Address Resolution Protocol (ARP) is a communication protocol used for discovering the link layer address (e.g. MAC address) that is associated with a given internet layer address, commonly IPv4.
The mapping function provided by ARP is critical to the Internet protocol suite and has been implemented with many combinations of network and data link layer technologies, such as IPv4, Chaosnet and DECnet using IEEE 802 standards, FDDI, X.25 and Frame Relay amongst others.
The File Transfer Protocol (FTP) standard defines an application layer network protocol to transfer files from a server to a client on a computer network.
FTP is based on a client-server model architecture using separate control and data connections between client and server.
The Hypertext Transfer Protocol (HTTP) is a standardized application layer protocol for distributed and collaborative, hypermedia information systems.
Alongside HTML, HTTP facilitated the development of original World Wide Web, the first interactive, text-based web browser.
IP routing encompasses different methodologies to route Internet Protocol (IP) packets within and across IP networks by determining a suitable path to transfer network packets between source and destination nodes in and across IP networks.
IP Routing protocols enable routers to build up a forwarding table that correlates final destinations with next hop addresses.
The Transmission Control Protocol (TCP) is one of the main protocols of the Internet protocol suite providing reliable, ordered, and error-checked byte stream deliveries between hosting applications communicating through an IP network.
Located in the Transport Layer of the TCP/IP suite, major internet applications such as the World Wide Web, email, SSL/TLS and file transfers rely on or run on top of TCP.
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iGrid has extensive experience in working with Ethernet and also the IP protocol suite, encpasulating, transfering, mapping and converting data and protocols accross many architectures, networks and application types.

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