Eigrp - Cisco Catalyst 4500 Series Configuration Manual

Chapter 1 Product Overview
BGP
The Border Gateway Protocol (BGP) is an exterior gateway protocol that allows you to set up an
interdomain routing system to automatically guarantee the loop-free exchange of routing information
between autonomous systems. In BGP, each route consists of a network number, a list of autonomous
systems that information has passed through (called the autonomous system path), and a list of other path
attributes.
The Catalyst 4500 series switch supports BGP version 4, including classless interdomain routing
(CIDR). CIDR lets you reduce the size of your routing tables by creating aggregate routes, resulting in
supernets. CIDR eliminates the concept of network classes within BGP and supports the advertising of
IP prefixes. CIDR routes can be carried by OSPF, EIGRP, and RIP.
BGP Route-Map Continue
The BGP Route-Map Continue feature introduces the continue clause to the BGP route-map
configuration. The continue clause provides more programmable policy configuration and route
filtering. It introduces the capability to execute additional entries in a route map after an entry is executed
with successful match and set clauses. Continue clauses allow configuring and organizing more modular
policy definitions to reduce the number of policy configurations that are repeated within the same route
map.
For details on BGP, refer to this URL:
http://www.cisco.com/en/US/docs/ios/12_4t/ip_route/configuration/guide/t_brbbas.html

EIGRP

The Enhanced Interior Gateway Routing Protocol (EIGRP) is a version of IGRP that combines the
advantages of link-state protocols with distance-vector protocols. EIGRP incorporates the Diffusing
Update Algorithm (DUAL). EIGRP includes fast convergence, variable-length subnet masks, partially
bounded updates, and multiple network-layer support. When a network topology change occurs, EIGRP
checks its topology table for a suitable new route to the destination. If such a route exists in the table,
EIGRP updates the routing table instantly. You can use the fast convergence and partial updates that
EIGRP provides to route Internetwork Packet Exchange (IPX) packets.
EIGRP saves bandwidth by sending routing updates only when routing information changes. The
updates contain information only about the link that changed, not the entire routing table. EIGRP also
takes into consideration the available bandwidth when determining the rate at which it transmits updates.
Note Layer 3 switching does not support the Next Hop Resolution Protocol (NHRP).
Note Customers can configure Enhanced Interior Gateway Routing Protocol (EIGRP) to route IPv6 prefixes.
EIGRP configuration and protocol behavior for both IPv4 and IPv6 prefixes are similar, providing
operational familiarity and continuity. EIGRP support for IPv6 will enable customers to use their
existing EIGRP knowledge and processes, allowing them to deploy an IPv6 network at a low cost.
For details on EIGRP, refer to this URL:
http://www.cisco.com/en/US/products/ps6630/products_ios_protocol_option_home.html
OL-25340-01
Software Configuration Guide—Release IOS XE 3.3.0SG and IOS 15.1(1)SG
Layer 3 Software Features
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