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Intermediate System to Intermediate System

IS-IS in an Interior Gateway Protocol developed in the 1980s by Digital Equipment Corporation (DEC) and submitted to the International Organization for Standardization (IOS) as the routing protocol for Open System Interconnection (OSI). The creation creation of IS-IS was an attempt to produce a standard protocol suite that could allow internetworks to scale.

In recent years, the IS-IS routing protocol has become increasingly popular, with widespread usage among Service Providers. It is a link state protocol, which enables very fast convergence with large scalability. It is also a very flexible protocol and has been extended to incorporate leading edge features such as MPLS Traffic Engineering.

The IS-IS routing protocol is a link-state protocol, as opposed to distance-vector protocols such as Interior Gateway Routing Protocol (IGRP) and Routing Information Protocol (RIP). Link-state offers several advantages over distance-vector protocols. It is faster converging, supports much larger internetworks, and is less susceptible to routing loops.

Intermediate System-to-Intermediate System (IS-IS) Protocol is an intradomain Open System Interconnection (OSI) dynamic routing protocol specified in International Organization for Standardization (ISO) 10589. The protocol is designed to operate in OSI Connectionless Network Service (CLNS). Data is carried using the protocol specified in ISO 8473.

Information about IS-IS from Cisco Systems


CategoryNetworking