NETWORK ROUTING PROTOCOLS

Network Routing Protocols

Abstract

This study aimed to understand the working of OSPF and IS-IS protocols. These protocols are among the most widely used IGP protocols used in the networking industry. In order to compare the merits and demerits of both the protocols, a critical analysis of the literary material available on the protocols was conducted. The important factors including scalability, security, performance and reliability were analyzed in the study. The two protocols are far more similar than different from each others. There are few factors that favor one protocol under certain conditions whereas; the other protocol takes the lead when comparison is done on certain other factors.Table of Contents

Introduction1

Literature Review1

SPF Algorithm2

IS-IS Routing Protocol4

Routing Procedure5

Similarities between OSPF & IS-IS6

Differences between OSPF & IS-IS7

Reliability & Security7

Stability8

Scalability9

Performance10

Comparison of OSPF & IS-IS10

Proposed Methodology11

Summary11

Network Routing Protocols

Introduction

A routing protocol is an important component of the network layer protocol. It controls and specifies the protocols through which a router communicates to another router. During that communication, it also directs how data is going to be routed in order to reach its node in a network. A routing protocol has an algorithm built-in to control the information flow. Every router in the group has knowledge of its neighboring routers; this is done by sharing the information of the next router in the network to its immediate neighbor (Oran 1990, 1).

Internet has been relaying on using RIP in order to route IP. OSPF, and IS-IS have been proposed as an alternative to RIP. This research paper attempts to compare and contrast the two routing protocols and how it affects the internet. There are many interesting differences and similarities between the two protocols, but a majority of these differences lie in theoretical concepts rather practically. However, there are some differences which clearly give an edge to one protocol. Therefore, it is imperative to understand the contrasting features of each protocol to find venues to further analysis and studies.

Literature Review

Open Shortest Path First (OSPF) was developed by the interior gateway protocol (IGP) working group at the Internet Engineering Task Force. It was made to serve as a better alternative to RIP for Internet Protocol (IP). The group had been formed in order to design a routing protocol based on the shortest path first (SPF) algorithm that was considered to offer a solution to the problems inherent in RIP. Routing Information Protocol (RIP) was unable to meet the demands of the large and complex networks that were emerging in the mid 1980s.

There are two characteristics of OSPF; one is the fact that the protocol is open and publicly available for anyone to use its specifications. Second is its foundation on the Dijkstra algorithm, which is commonly known as the OSPF algorithm (Nortel 2008, 45). OSPF algorithm sends link-state advertisements (LSAs) to all the routers present in the network. Every LSA has information regarding the interfaces and metrics integrated into it. When the routers have collected the LSA information, they are able to calculate the shortest path to connect to every node (ITO ...