Nortel Networks NN47200-503 manual RIP metrics, RIP hop counts

IP routing 25

•subnet mask (RIP version 2)

•routing table update based on the received RIP message

•global update timer

•holddown timer and timeout timer per device and per interface

•cost per device and per interface

The Nortel Ethernet Routing Switch 5500 Series implementation of RIP also supports the following features:

•in and out routing policies

•auto-aggregation (also known as auto-summarization) of groups of adjacent routes into single entries

Many RIP features are configurable. The actual behavior of the protocol depends on the feature configurations.

RIP metrics

RIP is known as a distance vector protocol. The vector is the network number and next hop, and the distance is the cost associated with the network number. RIP identifies network reachability based on cost, and cost is defined as hop count. The distance from one router to the next is considered to be one hop. This cost or hop count is known as the metric The illustration below depicts the hop counts between various units in a network.

RIP hop counts

A directly connected network has a metric of zero. An unreachable network has a metric of 16. Therefore, 15 hops or 15 routers is the highest possible metric between any two networks.

Nortel Ethernet Routing Switch 5500 Series

Configuration-IP Routing Protocols

NN47200-503 03.01 Standard

5.127 August 2007

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