Demand for IPv6 deployment is risinggradually and will no longer be an optional task but mandatory one, especiallyfor organizations that will require expansion in the near future.
Thedifference in packet structure between the two protocols (IPv4 and IPv6) meansthat routing traffic in IPv6 will no longer be supported by conventionalrouting protocols used in IPv4; hence new routing protocols that are compatiblewith IPv6 must be used. Even thoughthere are different IPv6 supported routing protocols like RIPng, EIGRPv6, IS–ISand OSPFv3 are still the most widely used in large networks. When largernetworks are considered, routed traffic also increases leading to a reductionin network stability.
Routing instability is found to be one of the majorcauses of network degradation in internet service performance. For example, anydisturbance in a network within a few hundreds of milliseconds is sufficient todisrupt voice or video transmission during protocol convergence. Voice packetsfor instance can be lost, delayed or suffer from jitter causing the network todegrade in performance. Therefore, for efficient data routing incommunication networks, implementation of a suitable routing protocol is acritical success factor to achieve high performance.
I.1 Thesis organizationThis thesis is organized into 4 chapters asfollows:Chapter 1 is an introduction about the background of the thesis work.Chapter 2 is a survey of related literature.
It also presents a detaileddiscussion of the two routing protocols in terms of their features, routingmetrics and fundamental concepts associated with them. Chapter 3 covers the methodology. It proposes the network topology for theentire thesis work and also covers the simulation. Chapter II IP Routing ProtocolsII.
1 Background The standard Internet Protocol known as IP isthe basic standard network layer on which are based most corporate networks. Thisprotocol allows communication among heterogeneous networks and is responsiblefor addressing and routing of packets between hosts and networks. The currentversion of IP that is widely used in the internet and private networks is knownas Internet Protocol Version 4 (IPv4). When IPv4 was first deployed, about 1,000computers were linked to it. The developers of the protocol did not imaginethat its 32–bit address size will not be enough to cope with the current growthrate of the internet (Andress, 2005).
Even though there were some techniquesincluding Network Address Translation (NAT) used to extend the address size.Unfortunately, IPv4 could still not be saved from address exhaustion problem.Besides its address space shortage, securing data within the IP layer, Qualityof Service and mobility issues were other challenges faced in IPv4. To tackle these limitation, the InternetProtocol version 6 (IPv6) was developed to replace IPv4. IPv6 is an innovativestep from IPv4 but has several improvements over its predecessor.
In IPv6, thetotal address space is extended from 32 bits to 128 bits, providing 2128(about 3.4 × 1038) IP addresses. This expansion means that assigningIP address to devices on the internet can now be done with much flexibility. IPv6 also has other features that offer manyadvantages over IPv4.
These are: · Quality of Service mechanisms: the header of IPv6 is designed to include QoS mechanisms. Insidethe header of IPv6 are the traffic class and the flow label fields that areintended for traffic classification in order to provide quality of service.With these two fields, nodes in IPv6 can distinguish certain packets so thatrouters can take special care of those packets.
Please refer to figure1.