Initially, Internet
Protocol was not designed with security in mind. When data security became
a major issue, different security techniques were developed but
implemented in the upper layers of the protocol suite to protect data from
unauthorized access. A new security
layer called IPsec was built into IPv6 to protect packets in the IP layer.
IPsec protects packets by providing integrity, confidentiality,
authentication and non–repudiation (Kent et al, 1998). Although IPsec can
also be used in IPv4, it is optional but not mandatory as in IPv6.
The differences in packet structures of both
protocols, the routing of IPv6 traffic is not supported by old routing
protocols. Also, considering the importance given to network scalability and
reliability during routing protocol implementation, development of dynamic
routing protocols supported by IPv6 became a necessity.
Routing protocols perform a vital job in every
communication network. Their major function is to forward packets received from
one network node to another. Routing protocols work by providing at least two
services:
Selecting best paths
between source and destination nodes, and
Successfully
transmitting data to a specified destination (Lemma et al., 2009).
When it comes to larger communication
networks, dynamic routing is preferred over static routing. Both static and
dynamic routing are just two ways by which routers can learn about remote
networks. In static routing, each network location must be entered into the routing
table by the network administrator. In dynamic routing, similar routing
protocols are configured on routers to enable them discover remote networks.
Using dynamic routing protocols on larger
networks saves time but it also consumes network resources. Dynamic routing
protocols are also more scalable; they automatically adapt to any change in
network topology. Also when there is a node or a route failure, they are able
to determine alternative routes and retransmit traffic via these routes with
minimal disruption.
Scalability is not the same for all routing
protocols. Some protocols are more scalable than others. Routing protocol
scalability is essential when considering current network growth rate.
Therefore when deciding on which routing protocol to implement on a network,
the protocol that scales well must be considered.
