Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Difference between IGRP and EIGRP
The distance-vector routing protocols IGRP (Interior Gateway Routing Protocol) and EIGRP (Enhanced Interior Gateway Routing Protocol) are both proprietary Cisco protocols used in enterprise networks. While IGRP was widely deployed in the 1980s and 1990s, EIGRP serves as its modern successor with significant improvements in performance and functionality.
Understanding the differences between these protocols is essential for network engineers working with Cisco infrastructure, as EIGRP has largely replaced IGRP in contemporary network deployments.
What is IGRP?
Interior Gateway Routing Protocol (IGRP) is a distance-vector routing protocol developed by Cisco Systems in the 1980s. It was designed to overcome the limitations of RIP by supporting larger networks and providing more sophisticated routing metrics.
IGRP uses a composite metric that considers bandwidth and delay as primary factors, with options to include reliability, load, and MTU. The protocol sends periodic routing updates every 90 seconds and has a maximum hop count of 100, making it suitable for medium-sized networks.
Key characteristics of IGRP include classful routing behavior, meaning it does not support Variable Length Subnet Masks (VLSM) or Classless Inter-Domain Routing (CIDR). This limitation restricts its flexibility in modern network designs that require efficient IP address allocation.
What is EIGRP?
Enhanced Interior Gateway Routing Protocol (EIGRP) is Cisco's advanced distance-vector routing protocol that replaced IGRP. It incorporates features from both distance-vector and link-state protocols, making it a hybrid routing protocol.
EIGRP uses the Diffusing Update Algorithm (DUAL) to ensure loop-free routing and rapid convergence. Unlike IGRP's periodic updates, EIGRP sends triggered updates only when network topology changes occur, significantly reducing network overhead and improving convergence times.
The protocol supports VLSM and CIDR, enabling efficient IP address utilization. EIGRP also provides unequal-cost load balancing, allowing traffic distribution across multiple paths with different metrics for optimal network utilization.
Key Differences
| Characteristic | IGRP | EIGRP |
|---|---|---|
| Algorithm | Distance Vector | Hybrid (DUAL) |
| Convergence Time | Slow | Fast |
| Administrative Distance | 100 | Internal: 90, External: 170 |
| Maximum Hop Count | 100 | 224 |
| Route Summarization | Classful | Classless |
| VLSM/CIDR Support | No | Yes |
| Update Method | Periodic (90 seconds) | Triggered updates |
| Load Balancing | Equal-cost only | Equal and unequal-cost |
Advantages and Disadvantages
IGRP Advantages
Simple configuration Easy to implement in small to medium networks
Reliable metric calculation Uses bandwidth and delay for accurate path selection
EIGRP Advantages
Rapid convergence DUAL algorithm ensures fast network adaptation
Efficient bandwidth usage Triggered updates reduce network overhead
Advanced features Supports VLSM, route summarization, and load balancing
Scalability Suitable for large enterprise networks
Conclusion
EIGRP represents a significant advancement over IGRP, offering faster convergence, better scalability, and support for modern networking requirements like VLSM and CIDR. While IGRP served networks well in the past, EIGRP is the preferred choice for contemporary Cisco network deployments due to its hybrid nature and advanced features.
2K+ Views
