Host (network)

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A network host is a computer or other device connected to a computer network. A host may work as a server offering information resources, services, and applications to users or other hosts on the network. Hosts are assigned at least one network address.

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A computer participating in networks that use the Internet protocol suite may also be called an IP host. Specifically, computers participating in the Internet are called Internet hosts. Internet hosts and other IP hosts have one or more IP addresses assigned to their network interfaces. The addresses are configured either manually by an administrator, automatically at startup by means of the Dynamic Host Configuration Protocol (DHCP), or by stateless address autoconfiguration methods.

Network hosts that participate in applications that use the client–server model of computing, are classified as server or client systems. Network hosts may also function as nodes in peer-to-peer applications, in which all nodes share and consume resources in an equipotent manner.

Origins

In operating systems, the term terminal host denotes a time-sharing computer or multi-user software providing services to computer terminals, or a computer that provides services to smaller or less capable devices, [1] such as a mainframe computer serving teletype terminals or video terminals. Other examples of this architecture include a telnet host connected to a telnet server and an xhost connected to an X Window client.

The term Internet host or just host is used in a number of Request for Comments (RFC) documents that define the Internet and its predecessor, the ARPANET. RFC 871 defines a host as a general-purpose computer system connected to a communications network for "... the purpose of achieving resource sharing amongst the participating operating systems..." [2]

While the ARPANET was being developed, computers connected to the network were typically mainframe computer systems that could be accessed from dumb terminals connected via serial ports. Since these terminals did not host software or perform computations themselves, they were not considered hosts as they were not connected to any IP network, and were not assigned IP addresses. User computers connected to the ARPANET at a packet-switching node were considered hosts. [3]

Nodes, hosts, and servers

A network node is any device participating in a network. A host is a node that participates in user applications, either as a server, client, or both. A server is a type of host that offers resources to the other hosts. Typically a server accepts connections from clients who request a service function. [4]

Every network host is a node, but not every network node is a host. Network infrastructure hardware, such as modems, Ethernet hubs, and network switches are not directly or actively participating in application-level functions, and do not necessarily have a network address, and are not considered to be network hosts.

See also

Related Research Articles

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<span class="mw-page-title-main">Network address translation</span> Protocol facilitating connection of one IP address space to another

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<span class="mw-page-title-main">Anycast</span> Network addressing and routing methodology

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<span class="mw-page-title-main">Terminal server</span> Device that interfaces serial hosts to a network

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<span class="mw-page-title-main">Computer network</span> Network that allows computers to share resources and communicate with each other

A computer network is a set of computers sharing resources located on or provided by network nodes. Computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are made up of telecommunication network technologies based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies.

A network socket is a software structure within a network node of a computer network that serves as an endpoint for sending and receiving data across the network. The structure and properties of a socket are defined by an application programming interface (API) for the networking architecture. Sockets are created only during the lifetime of a process of an application running in the node.

In computer networking, a port or port number is a number assigned to uniquely identify a connection endpoint and to direct data to a specific service. At the software level, within an operating system, a port is a logical construct that identifies a specific process or a type of network service. A port at the software level is identified for each transport protocol and address combination by the port number assigned to it. The most common transport protocols that use port numbers are the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP); those port numbers are 16-bit unsigned numbers.

In computing, a shared resource, or network share, is a computer resource made available from one host to other hosts on a computer network. It is a device or piece of information on a computer that can be remotely accessed from another computer transparently as if it were a resource in the local machine. Network sharing is made possible by inter-process communication over the network.

References

  1. ↑ E. Garrison Walters (2001). The essential guide to computing]. Prentice Hall PTR. p. 149. ISBN   9780130194695.
  2. ↑ M.A. Padlipsky (September 1982). A Perspective on the ARPANET Reference Model. doi: 10.17487/RFC0871 . RFC 871.
  3. ↑ Douglas E. Comer (2000). Internetworking with TCP/IP - Principles, Protocols and Architecture (4th ed.). Prentice Hall. p. 39. ISBN   0-13-018380-6.
  4. ↑ "Exchange Server architecture".
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