|
Routing Information Protocol
The Routing Information Protocol (RIP) is one of the oldest distance-vector routing protocols which employs the hop count as a routing metric. RIP prevents routing loops by implementing a limit on the number of hops allowed in a path from source to destination. The largest number of hops allowed for RIP is 15, which limits the size of networks that RIP can support. RIP implements the split horizon, route poisoning, and holddown mechanisms to prevent incorrect routing information from being propagated. In RIPv1 routers broadcast updates with their routing table every 30 seconds. In the early deployments, routing tables were small enough that the traffic was not significant. As networks grew in size, however, it became evident there could be a massive traffic burst every 30 seconds, even if the routers had been initialized at random times. In most networking environments, RIP is not the preferred choice of routing protocol, as its time to converge and scalability are poo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distance-vector Routing Protocol
A distance-vector routing protocol in data networks determines the best route for data packets based on distance. Distance-vector routing protocols measure the distance by the number of routers a packet has to pass; one router counts as one hop. Some distance-vector protocols also take into account network latency and other factors that influence traffic on a given route. To determine the best route across a network, routers using a distance-vector protocol exchange information with one another, usually routing tables plus hop counts for destination networks and possibly other traffic information. Distance-vector routing protocols also require that a router inform its neighbours of network topology changes periodically. Distance-vector routing protocols use the Bellman–Ford algorithm to calculate the best route. Another way of calculating the best route across a network is based on link cost, and is implemented through link-state routing protocols. The term ''distance vec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Assigned Numbers Authority
The Internet Assigned Numbers Authority (IANA) is a standards organization that oversees global IP address allocation, Autonomous system (Internet), autonomous system number allocation, DNS root zone, root zone management in the Domain Name System (DNS), Internet media type, media types, and other Internet Protocol–related symbols and Internet numbers. Currently it is a function of ICANN, a nonprofit private American corporation established in 1998 primarily for this purpose under a United States Department of Commerce contract. ICANN managed IANA directly from 1998 through 2016, when it was transferred to Public Technical Identifiers (PTI), an affiliate of ICANN that operates IANA today. Before it, IANA was administered principally by Jon Postel at the Information Sciences Institute (ISI) of the University of Southern California (USC) situated at Marina Del Rey (Los Angeles), under a contract USC/ISI had with the United States Department of Defense. In addition, five regional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IPv4
Internet Protocol version 4 (IPv4) is the first version of the Internet Protocol (IP) as a standalone specification. It is one of the core protocols of standards-based internetworking methods in the Internet and other packet-switched networks. IPv4 was the first version deployed for production on SATNET in 1982 and on the ARPANET in January 1983. It is still used to route most Internet traffic today, even with the ongoing deployment of Internet Protocol version 6 (IPv6), its successor. IPv4 uses a 32-bit address space which provides 4,294,967,296 (232) unique addresses, but large blocks are reserved for special networking purposes. Purpose The Internet Protocol ("IP") is the protocol that defines and enables internetworking at the internet layer of the Internet Protocol Suite. It gives the Internet a global-scale logical addressing system which allows the routing of IP Network packet, data packets from a source host to the next router that is one Hop (networking), hop closer t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daemon (computing)
In computing, a daemon is a program that runs as a background process, rather than being under the direct control of an interactive user. Customary convention is to name a daemon process with the letter ''d'' as a suffix to indicate that it's a daemon. For example, is a daemon that implements system logging facility, and is a daemon that serves incoming SSH connections. Even though the concept can apply to many computing systems, the term ''daemon'' is used almost exclusively in the context of Unix-based systems. In other contexts, different terms are used for the same concept. Systems often start daemons at boot time that will respond to network requests, hardware activity, or other programs by performing some task. Daemons such as cron may also perform defined tasks at scheduled times. Terminology In the context of computing, the word is generally pronounced either as or . The term was coined by the programmers at MIT's Project MAC. According to Fernando J. Cor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UNIX
Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others. Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Berkeley ( BSD), Microsoft (Xenix), Sun Microsystems ( SunOS/ Solaris), HP/ HPE ( HP-UX), and IBM ( AIX). The early versions of Unix—which are retrospectively referred to as " Research Unix"—ran on computers such as the PDP-11 and VAX; Unix was commonly used on minicomputers and mainframes from the 1970s onwards. It distinguished itself from its predecessors as the first portable operating system: almost the entire operating system is written in the C programming language (in 1973), which allows U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berkeley Software Distribution
The Berkeley Software Distribution (BSD), also known as Berkeley Unix or BSD Unix, is a discontinued Unix operating system developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berkeley, beginning in 1978. It began as an improved derivative of AT&T's original Unix that was developed at Bell Labs, based on the source code but over time diverging into its own code. BSD would become a pioneer in the advancement of Unix and computing. BSD's development was begun initially by Bill Joy, who added virtual memory capability to Unix running on a VAX-11 computer. In the 1980s, BSD was widely adopted by workstation vendors in the form of proprietary Unix distributions such as DEC Ultrix and Sun Microsystems SunOS due to its permissive licensing and familiarity to many technology company founders and engineers. It also became the most popular Unix at universities, where it was used for the study of operating systems. BSD was sponsored ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Novell
Novell, Inc. () was an American software and services company headquartered in Provo, Utah, that existed from 1980 until 2014. Its most significant product was the multi-platform network operating system known as NetWare. Novell technology contributed to the emergence of local area networks, which displaced the dominant mainframe computing model and changed computing worldwide. Under the leadership of chief executive Ray Noorda, NetWare became the dominant form of personal computer networking during the second half of the 1980s and first half of the 1990s. At its high point, NetWare had a 63 percent share of the market for network operating systems and by the early 1990s there were over half a million NetWare-based networks installed worldwide encompassing more than 50 million users. Novell was the second-largest maker of software for personal computers, trailing only Microsoft Corporation, and became instrumental in making Utah Valley a focus for technology and softw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xerox Network Systems
Xerox Network Systems (XNS) is a computer networking protocol suite developed by Xerox within the Xerox Network Systems Architecture. It provided general purpose network communications, internetwork routing and packet delivery, and higher level functions such as a reliable stream, and remote procedure calls. XNS predated and influenced the development of the Open Systems Interconnection (OSI) networking model, and was very influential in local area networking designs during the 1980s. XNS was developed by the Xerox Systems Development Department in the early 1980s, who were charged with bringing Xerox PARC's research to market. XNS was based on the earlier (and equally influential) PARC Universal Packet (PUP) suite from the late 1970s. Some of the protocols in the XNS suite were lightly modified versions of the ones in the Pup suite. XNS added the concept of a network number, allowing larger networks to be constructed from multiple smaller ones, with routers controlling the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xerox
Xerox Holdings Corporation (, ) is an American corporation that sells print and electronic document, digital document products and services in more than 160 countries. Xerox was the pioneer of the photocopier market, beginning with the introduction of the Xerox 914 in 1959, so much so that the word ''xerox'' is commonly used as a synonym for ''photocopy''. Xerox is headquartered in Norwalk, Connecticut, though it is incorporated in New York (state), New York with its largest group of employees based around Rochester, New York, the area in which the company was founded. As a large developed company, it is consistently placed in the list of Fortune 500 companies. The company purchased Affiliated Computer Services for $6.4 billion in early 2010. On December 31, 2016, Xerox separated its business process service operations, essentially those operations acquired with the purchase of Affiliated Computer Services, into a new publicly traded company, Conduent. Xerox focuses on its docu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CYCLADES
The CYCLADES computer network () was a French research network created in the early 1970s. It was one of the pioneering networks experimenting with the concept of packet switching and, unlike the ARPANET, was explicitly designed to facilitate internetworking. The CYCLADES network was the first to make the hosts responsible for the reliable delivery of data, rather than this being a centralized service of the network itself. Datagrams were exchanged on the network using transport protocols that do not guarantee reliable delivery, but only attempt best-effort. To empower the network leaves the hosts to perform error-correction, the network ensured end-to-end protocol transparency, a concept later to be known as the end-to-end principle. This simplified network design, reduced network latency, and reduced the opportunities for single point failures. The experience with these concepts led to the design of key features of the Internet Protocol in the ARPANET project. The network ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ARPANET
The Advanced Research Projects Agency Network (ARPANET) was the first wide-area packet-switched network with distributed control and one of the first computer networks to implement the TCP/IP protocol suite. Both technologies became the technical foundation of the Internet. The ARPANET was established by the Advanced Research Projects Agency (now DARPA) of the United States Department of Defense. Building on the ideas of J. C. R. Licklider, Robert Taylor (computer scientist), Bob Taylor initiated the ARPANET project in 1966 to enable resource sharing between remote computers. Taylor appointed Lawrence Roberts (scientist), Larry Roberts as program manager. Roberts made the key decisions about the request for proposal to build the network. He incorporated Donald Davies' concepts and designs for packet switching, and sought input from Paul Baran on dynamic routing. In 1969, ARPA awarded the contract to build the Interface Message Processors (IMPs) for the network to Bolt Berane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
