3Com Switch 8800 Advanced Software V5 Configuration Guide

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IPV6 RIPNG CONFIGURATION
When configuring RIPng, go to these sections for information you are interested
in:
■ “Introduction to RIPng” on page 289
■ “Configuring RIPng Basic Functions” on page 292
■ “Configuring RIPng Route Control” on page 292
■ “Tuning and Optimizing the RIPng Network” on page 294
■ “Displaying and Maintaining RIPng Configuration” on page 296
■ “RIPng Configuration Example” on page 297
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The term "router" in this document refers to a router in a generic sense or an
Ethernet switch running routing protocols.
Introduction to RIPng RIP next generation (RIPng) is an extension of RIP-2 for IPv4. Most RIP concepts are
applicable in RIPng.
RIPng for IPv6 made the following changes to RIP:
■ UDP port number: RIPng uses UDP port 521 for sending and receiving routing
information.
■ Multicast address: RIPng uses FF02:9 as the link-local multicast address.
■ Destination Prefix: 128-bit destination address prefix.
■ Next hop: 128-bit IPv6 address.
■ Source address: RIPng uses the link-local address as the source for sending
RIPng route updates.
RIPng Working
Mechanism
RIPng is a routing protocol based on the distance vector (D-V) algorithm. RIPng
uses UPD packets to exchange routing information through port 521.
RIPng uses a hop count to measure the distance to a destination. The hop count is
referred to as metric or cost. The hop count from a router to a directly connected
network is 0. The hop count between two directly connected routers is 1. When
the hop count is greater than or equal to 16, the destination network or host is
unreachable.
By default, the routing update is sent every 30 seconds. If the router receives no
routing updates from a neighbor after 180 seconds, the routes learned from the
neighbor are considered as unreachable. After another 240 seconds, if no routing
update is received, the router will remove these routes from the routing table.