IPv6 Routing - Internet Protocol version 6 (IPv6)

What is IPv6 Routing?

Through the process of routing, routable data is forwarded by choosing the best route among the various available routes or paths for destination. The data that is not explicitly destined to it is forwarded by using a router.

Routing protocol is of two forms:

• Distance Vector Routing Protocol: A router running distance vector protocol advertises its connected routes and learns new routes from its neighbors. Hops between the source and destination are considered for calculating the routing cost for reaching a destination. For selecting the best path, usually router relies on its neighbour known as “routing-by-rumors”. The Distance Vector Protocols are RIP and BGP.

• Link-State Routing Protocol: The state of the Link is acknowledged by this protocol and is advertised to the neighbours. Peer Routers help in learning information about new links. After all the routing information has been converged, its own algorithm is used by the Link-State Routing Protocol for calculating the best path to all the available links.

Routing protocols can be divided in two categories:

• Interior Routing Protocol: This category protocols are used within an autonomous system or organization for distributing the routes among all the routes inside the boundary. For instance, RIP, OSPF.
• Exterior Routing Protocol: This category protocol distributes the routing information between two different autonomous organizations or systems. For instance, BGP.

What are the different Routing protocols in IPv6?

RIPng

RIPng stands for Routing Information Protocol Next Generation. An internal Routing Protocol which is a Distance Vector Protocol is RIPng which has been upgraded for supporting IPv6.

OSPFv3

An interior Routing Protocol which has been modified for supporting IPv6 is Open Shortest Path First version 3. Djikrasta’s Shortest Path First algorithm is used for calculating the path for all destinations by this link-State Protocol.

BGPv4

BGP stands for Border Gateway Protocol. It is the only open standard Exterior Gateway Protocol available. BGP is a Distance Vector protocol which takes Autonomous System as calculation metric, instead of the number of routers as Hop. BGPv4 is an upgrade of BGP to support IPv6 routing.

What are the different Protocols that are changed to Support IPv6?

The following are some of the protocols that ate changed to support IPv6.

• ICMPv6: Internet Control Message Protocol version 6 is an upgraded implementation of ICMP for accommodating IPv6 requirements. For the purpose of information, statistics, functions and errors this protocol is used. ARP is replaced by the ICMPv6 Neighbour Discovery Protocol and helps in discovering the routers on the link.
• DHCPv6: Dynamic Host Configuration Protocol version 6 is an implementation of DHCP. In order to acquire IP address they need not be auto-configured as the IPv6 enabled hosts do not require any DHCPv6 server. The information can be provided by using the DHCPv6 Server.
• DNS: DNS has no versions but is equipped with some of the extensions for providing support to query the IPv6 address. In order to reply IPv6 query messages, a new AAAA (quad-A) record has been added. Without the changes in the query format, DNS can reply with both IP versions 4 and 6.