2.1. Vector Protocol Basics

A vector is defined as a quantity that has both magnitude and direction. An IP route is a vector, in which the direction is some egress interface or a next-hop address. How the route’s magnitude is defined varies from one protocol to another. It might be a distance measured in router hops (RIP), autonomous system hops (BGP), or a sum of interface characteristics (IGRP and EIGRP). The magnitude might also be a sum of dimensionless interface metrics (OSPF and IS-IS). But stating that a route is a vector is not really useful in differentiating vector protocols from link state protocols. A route derived by either is a vector.

My friend Paul Goyette points out that in virology, a vector is a means of propagation of some ...

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