Interior Gateway Routing Protocol (IGRP) is a distance-vector routing protocol developed by Cisco Systems for use within autonomous systems (ASes) in computer networks. It is designed to facilitate the exchange of routing information and the determination of the best paths for data packet forwarding within a single autonomous system.
Key characteristics of IGRP included:
- Distance-Vector Protocol: IGRP used a distance-vector algorithm to calculate the best paths to destination networks based on metrics like bandwidth and delay.
- Hierarchical Design: IGRP supported hierarchical network design, allowing networks to be divided into areas for better scalability and management.
- Routing Metrics: IGRP considered multiple routing metrics, such as bandwidth, delay, reliability, and load, to calculate the best routes.
It’s important to note that IGRP has largely been deprecated and replaced by more modern and advanced routing protocols, such as OSPF (Open Shortest Path First) and EIGRP (Enhanced Interior Gateway Routing Protocol). These newer protocols offer better scalability, faster convergence, and improved support for larger and more complex networks.
IGRP’s limitations in terms of scalability and convergence time contributed to its decline in usage, and it is no longer widely deployed in modern networks.