IPv6 RIP is an Interior Gateway Protocol (IGP) designed to manage a relatively small network. IPv6 RIP is based on the Bellman-Ford or the distance-vector algorithm. IPv6 RIP has limitations and is not suited for every TCP/IP environment. Before using the IPv6 RIP function in OMPROUTE, read RFC 2080 to decide if RIP can be used to manage the IPv6 routing tables of your network. For more information about RFC 2080, see Related protocol specifications.
IPv6 RIP uses the number of hops, or hop count, to determine the best possible route to a host or network. The term hop count is also referred to as the metric. In IPv6 RIP, a hop count of 16 means infinity, or that the destination cannot be reached. This limits the longest path in the network that can be managed by IPv6 RIP to 15 gateways.
A IPv6 RIP router broadcasts routing information to its directly connected networks every 30 seconds. It receives updates from neighboring IPv6 RIP routers every 30 seconds and uses the information contained in these updates to maintain the IPv6 routing table. If an IPv6 RIP update has not been received from a neighboring router in 180 seconds, an IPv6 RIP router assumes that the neighboring router is down, sets all IPv6 RIP routes through that router to a metric of 16 (infinity), and stops using those routes when routing IP packets. If an update has still not been received from the neighboring router after another 120 seconds, the IPv6 RIP router deletes from the IPv6 routing table all of the IPv6 RIP routes through that neighboring router.
Next hop IP addresses, whenever applicable, are included in IPv6 RIP updates to eliminate packets being routed through extra hops in the network. IPv6 multicast address FF02::9, reserved for IPv6 RIP packets, is used to reduce unnecessary load on hosts that are not listening for IPv6 RIP messages.
For configuration information for IPv6 RIP, see Steps for configuring OSPF and RIP (IPv4 and IPv6).