ECS4660-28F_Management Guide-R03

– 769 –
20 UNICAST ROUTING
This chapter describes how to configure the following unicast routing
protocols:
RIP – Configures Routing Information Protocol.
OSPFv2 – Configures Open Shortest Path First (Version 2) for IPv4.
OVERVIEW
This switch can route unicast traffic to different subnetworks using the
Routing Information Protocol (RIP) or Open Shortest Path First (OSPF)
protocol. It supports RIP, RIP-2 and OSPFv2 dynamic routing in the web
management interface. These protocols exchange routing information,
calculate routing tables, and can respond to changes in the status or
loading of the network. For information on configuring OSPFv3 and BGPv4,
refer to the appropriate sections under Chapter 54: IP Routing Commands.
RIP and RIP-2 Dynamic Routing Protocols
The RIP protocol is the most widely used routing protocol. RIP uses a
distance-vector-based approach to routing. Routes are determined on the
basis of minimizing the distance vector, or hop count, which serves as a
rough estimate of transmission cost. Each router broadcasts its
advertisement every 30 seconds, together with any updates to its routing
table. This allows all routers on the network to learn consistent tables of
next hop links which lead to relevant subnets.
OSPFv2 Dynamic Routing Protocols
OSPF overcomes all the problems of RIP. It uses a link state routing
protocol to generate a shortest-path tree, then builds up its routing table
based on this tree. OSPF produces a more stable network because the
participating routers act on network changes predictably and
simultaneously, converging on the best route more quickly than RIP.
Moreover, when several equal-cost routes to a destination exist, traffic can
be distributed equally among them.
Non-IP Protocol Routing
The switch supports IP routing only. Non-IP protocols such as IPX and
Appletalk cannot be routed by this switch, and will be confined within their
local VLAN group unless bridged by an external router.
To coexist with a network built on multilayer switches, the subnetworks for
non-IP protocols must follow the same logical boundary as that of the IP
subnetworks. A separate multi-protocol router can then be used to link the