An interior gateway protocol (IGP) or Interior routing protocol is a type of

routing protocol A routing protocol specifies how routers communicate with each other to distribute information that enables them to select routes between nodes on a computer network. Routers perform the traffic directing functions on the Internet; data packets ...

used for exchanging

routing table In computer networking, a routing table, or routing information base (RIB), is a data table stored in a router or a network host that lists the routes to particular network destinations, and in some cases, metrics (distances) associated with tho ...

information between gateways (commonly routers) ''within'' an autonomous system (for example, a system of corporate local area networks). This routing information can then be used to route network-layer protocols like IP. Interior gateway protocols can be divided into two categories:

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 ...

s and

link-state routing protocol Link-state routing protocols are one of the two main classes of routing protocols used in packet switching networks for computer communications, the others being distance-vector routing protocols. Examples of link-state routing protocols includ ...

s. Specific examples of IGPs include

Open Shortest Path First Open Shortest Path First (OSPF) is a routing protocol for Internet Protocol (IP) networks. It uses a link state routing (LSR) algorithm and falls into the group of interior gateway protocols (IGPs), operating within a single autonomous syst ...

(OSPF),

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 sour ...

(RIP),

Intermediate System to Intermediate System Intermediate System to Intermediate System (IS-IS, also written ISIS) is a routing protocol designed to move information efficiently within a computer network, a group of physically connected computers or similar devices. It accomplishes this b ...

(IS-IS) and

Enhanced Interior Gateway Routing Protocol Enhanced Interior Gateway Routing Protocol (EIGRP) is an advanced distance-vector routing protocol that is used on a computer network for automating routing decisions and configuration. The protocol was designed by Cisco Systems as a proprietar ...

(EIGRP). By contrast,

exterior gateway protocol An exterior gateway protocol is an IP routing protocol used to exchange routing information between autonomous systems. This exchange is crucial for communications across the Internet. Notable exterior gateway protocols include Exterior Gateway ...

s are used to exchange routing information ''between'' autonomous systems and rely on IGPs to resolve routes within an autonomous system.

Examples

Examples of distance-vector routing protocols: *

(RIP) * Routing Information Protocol Version 2 (RIPv2) * Routing Information Protocol Next Generation (RIPng), an extension of RIP version 2 with support for

IPv6 Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communication protocol, communications protocol that provides an identification and location system for computers on networks and routes traffic ...

Interior Gateway Routing Protocol Interior Gateway Routing Protocol (IGRP) is a distance vector interior gateway protocol (IGP) developed by Cisco. It is used by routers to exchange routing data within an autonomous system. IGRP is a proprietary protocol. IGRP was created in ...

(IGRP) Examples of link-state routing protocols: *

(OSPF) *

Intermediate system to intermediate system Intermediate System to Intermediate System (IS-IS, also written ISIS) is a routing protocol designed to move information efficiently within a computer network, a group of physically connected computers or similar devices. It accomplishes this b ...

(IS-IS) Advanced distance vector routing protocols have both the features of distance vector routing protocols and link-state routing protocols. One example is

(EIGRP).

References

{{DEFAULTSORT:Interior Gateway Protocol Routing protocols

Examples

See also

References