Sso Aware Hsrp - Cisco Catalyst 4500 Series Software Configuration 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.
NHRP
Beginning in Cisco IOS XE Release 3.7.1E, NHRP is supported on Catalyst 4500 series switches.
The Next Hop Resolution Protocol (NHRP) is an ARP-like protocol that dynamically maps a
Non-Broadcast Multi-Access (NBMA) network. With NHRP, systems attached to an NBMA network
can dynamically learn the NBMA (physical) address of the other systems that are part of that network,
allowing these systems to directly communicate.
NHRP is a client and server protocol where the hub is the Next Hop Server (NHS) and the spokes are
the Next Hop Clients (NHCs). Catalyst 4500 series switches act as NHRP clients that communicate with
the NHRP hub for registration, and to request the resolution of other spoke addresses.
Note Catalyst 4500 series switches cannot be used as NHRP hubs.
For information on configuring NHRP, see
http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipaddr_nhrp/configuration/xe-3s/asr1000/nhrp-xe-3s
-asr1000-book/config-nhrp.html
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.
BGP, page 1-17
EIGRP, page 1-18
IS-IS, page 1-18
OSPF, page 1-19
RIP, page 1-19
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Layer 3 Software Features
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