This article is chiefly about the Routing Information Protocol (RIP) for the Internet Protocol, but also discusses some other routing information protocols.

The Routing Information Protocol (RIP) was one of the most commonly used interior gateway protocol (IGP) routing protocols on internal networks (and to a lesser extent, networks connected to the Internet), which helps routers dynamically adapt to changes of network connections by communicating information about which networks each router can reach and how far away those networks are. The network layer is third layer out of seven in OSI model and it is the third layer out of five in TCP/IP model. ... The Internet Protocol (IP) is a data-oriented protocol used for communicating data across a packet-switched internetwork. ... Internet Protocol version 4 is the fourth iteration of the Internet Protocol (IP) and it is the first version of the protocol to be widely deployed. ... Internet Protocol version 6 (IPv6) is a network layer protocol for packet-switched internetworks. ... The Open Shortest Path First (OSPF) protocol is a hierarchical interior gateway protocol (IGP) for routing in Internet Protocol, using a link-state in the individual areas that make up the hierarchy. ... Is Is is Yeah Yeah Yeahs third EP, to be released on July 24, 2007. ... The Border Gateway Protocol (BGP) is the core routing protocol of the Internet. ... IPsec (IP security) is a suite of protocols for securing Internet Protocol (IP) communications by authenticating and/or encrypting each IP packet in a data stream. ... In computer networking, the Address Resolution Protocol (ARP) is the standard method for finding a hosts hardware address when only its network layer address is known. ... Reverse Address Resolution Protocol (RARP) is a network layer protocol used to obtain an IP address for a given hardware address (such as an Ethernet address). ... This article does not cite any references or sources. ... IEEE 802. ... Official Wi-Fi logo Wi-Fi (pronounced wye-fye, IPA: ), also unofficially known as Wireless Fidelity, is a wireless technology brand owned by the Wi-Fi Alliance intended to improve the interoperability of wireless local area network products based on the IEEE 802. ... Official WiMax logo WiMAX, the Wireless Interoperability for Microwave Access, is a telecommunications technology aimed at providing wireless data over long distances in a variety of ways, from point-to-point links to full mobile cellular type access. ... Asynchronous Transfer Mode (ATM) is a cell relay, packet switching network and data link layer protocol which encodes data traffic into small (53 bytes; 48 bytes of data and 5 bytes of header information) fixed-sized cells. ... Dynamic synchronous Transfer Mode , or DTM for short, is a network protocol. ... Token-Ring local area network (LAN) technology was developed and promoted by IBM in the early 1980s and standardised as IEEE 802. ... Ethernet is a large, diverse family of frame-based computer networking technologies that operate at many speeds for local area networks (LANs). ... In computer networking, fiber-distributed data interface (FDDI) is a standard for data transmission in a local area network that can extend in range up to 200 km (124 miles). ... In the context of computer networking, frame relay consists of an efficient data transmission technique used to send digital information quickly and cheaply in a relay of frames to one or many destinations from one or many end-points. ... General Packet Radio Service (GPRS) is a Mobile Data Service available to users of Global System for Mobile Communications (GSM) and IS-136 mobile phones. ... Evolution-Data Optimized or Evolution-Data only, abbreviated as EV-DO or EVDO and often EV, is one telecommunications standard for the wireless transmission of data through radio signals, typically for broadband Internet access. ... High-Speed Packet Access (HSPA) is a collection of mobile telephony protocols that extend and improve the performance of existing UMTS protocols. ... High-Level Data Link Control (HDLC) is a bit-oriented synchronous data link layer protocol developed by the International Organization for Standardization (ISO). ... In computing, the Point-to-Point Protocol, or PPP, is commonly used to establish a direct connection between two nodes. ... In computer networking, the Layer 2 Tunneling Protocol (L2TP) is a tunneling protocol used to support virtual private networks (VPNs). ... ISDN redirects here. ... This article does not cite any references or sources. ... IEEE photograph of a diagram with the original terms for describing Ethernet drawn by Robert M. Metcalfe around 1976. ... For other uses, see Modem (disambiguation). ... For other uses, see Power band. ... It has been suggested that this article be split into articles entitled Synchronous optical networking, SONET and Synchronous digital hierarchy. ... There are very few or no other articles that link to this one. ... Orthogonal Frequency-Division Multiplexing (OFDM) — essentially identical to Coded OFDM (COFDM) — is a digital multi-carrier modulation scheme, which uses a large number of closely-spaced orthogonal sub-carriers. ... Optical fibers An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length by confining as much light as possible in a propagating form. ... Coaxial Cable For the weapon, see coaxial weapon. ... 25 Pair Color Code Chart 10BASE-T UTP Cable Twisted pair cabling is a common form of wiring in which two conductors are wound around each other for the purposes of cancelling out electromagnetic interference known as crosstalk. ... The Internet Protocol (IP) is a data-oriented protocol used for communicating data across a packet-switched internetwork. ... A set of routing protocols that are used within an autonomous system are referred to as interior gateway protocols (IGP). ... Routing protocols allow different computer networks to communicate. ... This article is about a computer networking device. ...

Although RIP is still actively used, it is generally considered to have been made obsolete by routing protocols such as OSPF and IS-IS. Nonetheless, a somewhat more capable protocol in the same basic family (distance-vector routing protocols), was Cisco's proprietary (IGRP) Interior Gateway Routing Protocol. Cisco does not support IGRP in current releases of its software. It was "replaced" by EIGRP, the Enhanced Interior Gateway Routing Protocol, which is a completely new design. While EIGRP is still technically distance vector, it relates to IGRP only in having a similar name. The Open Shortest Path First (OSPF) protocol is a hierarchical interior gateway protocol (IGP) for routing in Internet Protocol, using a link-state in the individual areas that make up the hierarchy. ... Is Is is Yeah Yeah Yeahs third EP, to be released on July 24, 2007. ... This article does not cite any references or sources. ... Cisco may refer to: Cisco Systems, a computer networking company Cisco IOS, an internet router operating system CISCO Security Private Limited, a security company in Singapore Commercial and Industrial Security Corporation, a statutory board in Singapore Abbreviation for San Francisco, California Cisco (wine) The Cisco Kid, a fictional character created... Interior Gateway Routing Protocol (IGRP) is a kind of IGP which is a distance-vector routing protocol invented by Cisco, used by routers to exchange routing data within an autonomous system. ... Enhanced Interior Gateway Routing Protocol (EIGRP) is a Cisco proprietary routing protocol based on their original IGRP. EIGRP is a distance vector routing protocol, with optimizations to minimize both the routing instability incurred after topology changes, as well as the use of bandwidth and processing power in the router. ...

RIP is sometimes said to stand for Rest in Pieces in reference to the reputation that RIP has for breaking unexpectedly, rendering a network unable to function. [1]

History

The routing algorithm used in RIP, the Bellman-Ford algorithm, was first deployed in a computer network in 1969, as the initial routing algorithm of the ARPANET. In mathematics, computing, linguistics, and related disciplines, an algorithm is a finite list of well-defined instructions for accomplishing some task that, given an initial state, will terminate in a defined end-state. ... The Bellman–Ford algorithm computes single-source shortest paths in a weighted digraph (where some of the edge weights may be negative). ... ARPANET logical map, March 1977. ...

The earliest version of the specific protocol that became RIP was the Gateway Information Protocol, part of Xerox Parc's PARC Universal Packet internetworking protocol suite. A later version, named the Routing Information Protocol, was part of Xerox Network Services. Bold text // Headline text Link title This article is about the computer research center. ... The PARC Universal Packet (commonly abbreviated to PUP, although the original documents usually use Pup) was one of the two earliest internetwork protocol suites; it was created by researchers at Xerox PARC in the mid-1970s. ... Internetworking involves connecting two or more distinct computer networks together into an internetwork (often shortened to internet), using devices called routers to connect them together, to allow traffic to flow back and forth between them. ... Xerox network services (XNS) is a protocol stack which provided routing and packet delivery developed by Xerox at Xerox PARC in the later 1970s and early 1980s. ...

A version of RIP which supported the Internet Protocol (IP) was later included in the Berkeley Software Distribution (BSD) of the Unix operating system as the routed daemon, and various other vendors would implement their own implementations of the routing protocol. Eventually RFC 1058 was issued to unify the various implementations under a single standard. The Internet Protocol (IP) is a data-oriented protocol used for communicating data across a packet-switched internetwork. ... “BSD” redirects here. ... Filiation of Unix and Unix-like systems Unix (officially trademarked as UNIX®) is a computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy. ... In Unix and other computer multitasking operating systems, a daemon is a computer program that runs in the background, rather than under the direct control of a user; they are usually instantiated as processes. ...

Technical detail

RIP is a distance-vector routing protocol, which employs the hop count as a routing metric. The maximum number of hops allowed with RIP is 15, and the hold down time is 180 seconds. Originally each RIP router transmits full updates every 30 seconds by default. Originally, routing tables were small enough that the traffic was not significant. This article does not cite any references or sources. ...

As networks grew in size, however, it became evident there could be a massive burst every 30 seconds, even if the routers had been initialized at random times. It was thought, as a result of random initialization, the routing updates would spread out in time, but this was not true in practice. Sally Floyd and Van Jacobson published research in 1994 ^[1] that showed having all routers use a fixed 30 second timer was a very bad idea. Without slight randomization of the update timer, this research showed that the timers weakly synchronized over time and sent their updates out at the same time. Modern RIP implementations introduce deliberate time variation into the update timer of each router.

It runs at the network layer of the Internet protocol suite. RIP prevents routing loops from continuing indefinitely by implementing a limit on the number of hops allowed in a path from the source to a destination. This hop limit, however, limits the size of networks that RIP can support. The network layer is third layer out of seven in OSI model and it is the third layer out of five in TCP/IP model. ... The Internet protocol suite is the set of communications protocols that implement the protocol stack on which the Internet and most commercial networks run. ...

RIP implements the split horizon and holddown mechanisms to prevent incorrect routing information from being propagated. These are some of the stability features of RIP. The split horizon rule prohibits a router from advertising a route through an interface that the router itself is using to reach the destination. ... Holddowns are the method by which routing protocols prevent unstable network conditions from causing unnecessary or premature route propagation. ...

In many current networking environments RIP would not be the first choice for routing as its convergence times and scalability are poor compared to EIGRP, OSPF, or IS-IS (the latter two being link-state routing protocols), and the hop limit severely limits the size of network it can be used in. On the other hand, it is easier to configure because, using minimal settings for any routing protocols, RIP does not require any parameter on a router whereas all the other protocols require at least one or more parameters. The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... Enhanced Interior Gateway Routing Protocol (EIGRP) is a Cisco proprietary routing protocol based on their original IGRP. EIGRP is a balanced hybrid IP routing protocol, with optimizations to minimize both the routing instability incurred after topology changes, as well as the use of bandwidth and processing power in the router. ... The Open Shortest Path First (OSPF) protocol is a hierarchical interior gateway protocol (IGP) for routing in Internet Protocol, using a link-state in the individual areas that make up the hierarchy. ... Is Is is Yeah Yeah Yeahs third EP, to be released on July 24, 2007. ... A link-state routing protocol is one of the two main classes of routing protocols used in packet-switched networks for computer communications. ...

Architecturally, RIP is a layer management protocol for what is called the Internetwork Layer in the Internet protocol suite or the Network Layer in the OSI Reference Model. While it is carried in end-to-end (IPS) or transport layer (OSI) packets, using port number 520 in the User Datagram Protocol (UDP), as a routing protocol, it belongs to the network layer, not the layer that moves its packets. The Internet protocol suite is the set of communications protocols that implement the protocol stack on which the Internet and most commercial networks run. ... User Datagram Protocol (UDP) is one of the core protocols of the Internet protocol suite. ...

Versions

There are three IP versions of RIP, RIPv1, RIPv2, and RIPng. An earlier version of RIP supported the Xerox Network Services protocol suite.

RIPv1

RIPv1, defined in RFC 1058, uses classful routing. The routing updates do not carry subnet information, lacking support for variable length subnet masks (VLSM). This limitation makes it impossible to have different-sized subnets inside of the same network class. In other words, all subnets in a network class must be the same size. There is also no support for router authentication, making RIPv1 slightly vulnerable to various attacks. Classful networking is the name given to the first round of changes to the structure of the IP address in IPv4. ... A graphic representation of relationships and source of the various variables representing a chunk of C subnets In computer networks, a subnetwork or subnet is a range of logical addresses within the address space that is assigned to an organization. ... Classless Inter-Domain Routing (CIDR), introduced starting in 1993, is the latest refinement to the way IP addresses are interpreted. ... A graphic representation of relationships and source of the various variables representing a chunk of C subnets In computer networks, a subnetwork or subnet is a range of logical addresses within the address space that is assigned to an organization. ... ...

RIPv2

Due to the above deficiencies of RIPv1, RIPv2 was developed in 1994 and included the ability to carry subnet information, thus supporting Classless Inter-Domain Routing (CIDR). However to maintain backwards compatibility the 15 hop count limit remained. Rudimentary plain text authentication was added to secure routing updates; later, MD5 authentication was defined in RFC 2082. Also, in an effort to avoid waking up hosts that do not participate in the routing protocol, RIPv2 multicasts routing updates to 224.0.0.9, as opposed to RIPv1 which uses broadcast. Warning! This Article contains disinformation. ... In cryptography, MD5 (Message-Digest algorithm 5) is a widely used cryptographic hash function with a 128-bit hash value. ...

RIPv2 is specified in RFC 2453 or STD 56. An Internet standard is a specification for an innovative internetworking technology or methodology, which the Internet Engineering Task Force (IETF) ratified as an open standard after the innovation underwent peer review. ...

RIPng

RIPng, defined in RFC 2080, is an extension of Ripv2 original protocol to support IPv6. The main differences between RIPng and RIPv2 are: Internet Protocol version 6 (IPv6) is a network layer protocol for packet-switched internetworks. ...

• RIPv2 supports RIP updates authentication, RIPng does not (IPv6 routers were, at the time, supposed to use IPsec for authentication);
• RIPv2 allows attaching arbitrary tags to routes, RIPng does not;
• RIPv2 encodes the nexthop into each route entries, RIPng requires specific encoding of the nexthop for a set of route entries.

See also

• Border Gateway Protocol (BGP)
• Open Shortest Path First (OSPF) protocol
• IPX
• RFC

The Border Gateway Protocol (BGP) is the core routing protocol of the Internet. ... The Open Shortest Path First (OSPF) protocol is a hierarchical interior gateway protocol (IGP) for routing in Internet Protocol, using a link-state in the individual areas that make up the hierarchy. ... See also Ericsson IPX Internetwork Packet Exchange (IPX) is the OSI-model Network layer protocol in the IPX/SPX protocol stack. ... In internetworking and computer network engineering, Request for Comments (RFC) documents are a series of memoranda encompassing new research, innovations, and methodologies applicable to Internet technologies. ...

External references

• RIP - RFC 1058
• RIPng - RFC 2080
• RIPv2 - RFC 2453

Implementations

• routed, included in most BSD Unix systems
• 6WINDGate - 6WIND, commercial embedded open-source routing modules
• Quagga, a fork of GNU Zebra for Unix-like systems

Quagga is a free software routing suite, providing implementations of OSPF (v2 & v3), RIP (v1, v2 & v3) and BGP (v4) for Unix platforms, particularly FreeBSD, GNU/Linux, Solaris and NetBSD. Quagga is a fork of the GNU Zebra project (inactive since 2003) which was developed by Kunihiro Ishiguro. ... Diagram of the relationships between several Unix-like systems A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification. ...

References

1. ^ The Synchronization of Periodic Routing Messages, S. Floyd & V. Jacobson,April 1994

Further reading

• Edward A. Taft, Gateway Information Protocol (revised) (Xerox Parc, Palo Alto, May, 1979)
• Xerox System Integration Standard - Internet Transport Protocols (Xerox, Stamford, 1981)