RIPng, also called RIP next generation, is the RIP-2 extension used on IPv4 networks. RIP and RIPng share many concepts.
RIPng, based on the Distance Vector (D-V) algorithm, is a routing protocol that measures the distance (metric or cost) to a destination host by Hop Count (HC). RIPng defines that the HC from a router to its directly connected network is 0, and the HC from a router to a network that is reachable through another router is 1, and so on. When the HC reaches 16, the destination network or host is defined as unreachable.
RIPng is derived from RIP and applies to IPv6 networks. Unlike RIP, RIPng has the following characteristics:
UDP port number
RIPng uses UDP port number 521 (RIP uses UDP port number 520) to send and receive routing information.
Multicast address
RIPng uses FF02::9 as the multicast address on a RIPng router in the local link scope.
Prefix length
RIPng uses a 128-bit (the mask length) prefix in a destination address.
Next hop address
RIPng uses a 128-bit IPv6 address.
Source address
RIPng uses link-local address FE80::/10 as a source address used to send RIPng Update packets.
RIPng is developed by extending RIP and supports IPv6.