Eigrp - Cisco Catalyst 4500 Series Software Configuration Manual

Layer 3 Software Features
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).
Customers can configure Enhanced Interior Gateway Routing Protocol (EIGRP) to route IPv6 prefixes.
Note
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
IS-IS
The Intermediate System-to-Intermediate System Protocol (IS-IS Protocol) uses a link-state routing
algorithm. It closely follows the Open Shortest Path First (OSPF) routing protocol used within the
TCP/IP environment. The operation of ISO IS-IS Protocol requires each router to maintain a full
topology map of the network (that is, which intermediate systems and end systems are connected to
which other intermediate systems and end systems). Periodically, the router runs an algorithm over its
map to calculate the shortest path to all possible destinations.
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
1-18
Chapter 1 Product Overview