Sso Aware Hsrp - Cisco Catalyst 4500 series Administration Manual

Chapter 1 Product Overview

SSO Aware HSRP

SSO Aware HSRP offers continuous data packet forwarding during a supervisor engine switchover
without a path change to the standby HSRP router. During supervisor engine switchover, NSF with SSO
continues forwarding data packets along known routes using the HSRP virtual IP address. When both
supervisor engines fail on the active HSRP router, the standby HSRP router takes over as the active
HSRP router. It further extends reliability and availability offered by the NSF with SSO to Layer 3. SSO
aware HSRP is available for Supervisor Engine IV, V, and V-10GE on Catalyst 4507R and 4510R chassis
with supervisor redundancy.
IP Routing Protocols
The following routing protocols are supported on the Catalyst 4500 series switch:
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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
OL-30933-01
BGP, page 1-17
EIGRP, page 1-17
IS-IS, page 1-18
OSPF, page 1-18
RIP, page 1-19
Software Configuration Guide—Release IOS XE 3.6.0E and IOS 15.2(2)E
Layer 3 Software Features
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