Ripng; Introduction To Ripng - Edge-Core ES4624-SFP Routing Management Manual

RIP for all vrf.
Default: Not shown by default.
Command Mode: Admin Mode and Configuration Mode.
Usage Guide: None.
Example:
Switch#show ip rip redistribute

1.5 RIPng

1.5.1 Introduction to RIPng

RIPng is first introduced in ARPANET, this is a protocol dedicated to small, simple networks.
RIPng is a distance vector routing protocol based on the Bellman-Ford algorithm. Network
devices running vector routing protocol send 2 kind of information to the neighboring devices
regularly:

Number of hops to reach the destination network, or metrics to use or number of networks
to pass.

What is the next hop, or the director (vector) to use to reach the destination network.
Distance vector layer3 switches send all their route selecting tables to the neighbor layer3
switches at regular interval. A layer3 switch will build their own route selecting information table
based on the information received from the neighbor layer3 switches. Then, it will send this
information to its own neighbor layer3 switches. As a result, the route selection table is built on
second hand information, route beyond 15 hops will be deemed as unreachable.
RIPng is an optional routing protocol based on UDP. Hosts using RIPng send and receive
packets on UDP port 521. All layer3 switches running RIP send their route table to all neighbor
layer3 switches every 30 seconds for update. If no information from the partner is received in
180 seconds, then the device is deemed to have failed and the network connected to that device
is considered to be unreachable. However, the route of that layer3 switch will be kept in the route
table for another 120 seconds before deletion.
As layer3 switches running RIPng build route table with second hand information, infinite
count may occur. For a network running RIPng routing protocol, when a RIPng route becomes
unreachable, the neighboring RIPng layer3 switch will not send route update packets at once,
instead, it waits until the update interval timeout (every 30 seconds) and sends the update
packets containing that route. If before it receives the updated packet, its neighbors send
packets containing the information about the failed neighbor, "infinite count" will be resulted. In
other words, the route of unreachable layer3 switch will be selected with the metrics increasing
progressively. This greatly affects the route selection and route aggregation time.
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