IP routing is a technique for routing a packet to a single destination by using an IP routing protocol to determine the path to that destination.
IP routing protocols are often categorized as distance-vector type or link-state type. Distance-vector routing protocols maintain a list of the distances to other networks in hops, the number of routers crossed. If your switch has Layer 3 capability, it supports three distance-vector protocols: Routing Information Protocol (RIP), Interior Gateway Routing Protocol (IGRP), and Enhanced Interior Gateway Routing Protocol (EIGRP). Link-state routing protocols use a metric based on link speed to represent the distance to other networks. Link-state routers maintain a map a map that shows alternate routes or parallel paths for load balancing. If your switch has Layer 3 capability, the link-state routing protocol it supports is Open Shortest Path First (OSPF).
To enable IP routing, you specify the minimal information needed to configure routing on SVIs and routed ports. You perform this task by selecting Device > IP Routing > Protocols, and using the IP Routing window. If you want to configure advanced routing options, click Advanced in this window.
Overview of IGRP and
EIGRP
Overview
of OSPF
"Configuring IP Unicast Routing," Catalyst
3550 Multilayer Switch Software Configuration Guide