Hardware and Software Prerequisites

Enabling High Availability Features

•Cisco Nonstop Forwarding (NSF) —Used with SSO, NSF allows routers with redundant RSPs to continue forwarding data to the standby RSP during a switchover. This feature uses the Forwarding Information Base (FIB) that was current at the time of the switchover. Once the routing protocols have converged, the FIB table is updated and stale route entries are deleted. This feature eliminates downtime during the switchover. Note: Cisco NSF always runs together with SSO.

Cisco NSF is supported by the BGP, OSPF, and IS-IS protocols for routing and by Cisco Express Forwarding (CEF) for forwarding. For more information on how to configure NSF, see the Cisco Nonstop Forwarding feature module available online at http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120limit/120s/120s22 /nsf120s.htm.

The RPR and FSU features are available on the Cisco 7507, Cisco 7507-MX, Cisco 7513, and

Cisco 7513-MX routers, which are loaded with two route switch processors (RSPs). The router is loaded with two route switch processors (RSPs), which can be two RSP8s, or an RSP16 and an RSP8.

The following HA features became available on the following minimum software releases:

•Single Line Card Reload (SLCR)—Cisco IOS Releases 12.0(13)S, 12.1(4)T, and 12.1(5)E

•Route Processor Redundancy (RPR)— Cisco IOS Release 12.0(16)ST

•Route Processor Redundancy Plus (RPR+)— Cisco IOS Release 12.0(19)ST

•Fast Software Upgrade (FSU)—Cisco IOS Release 12.0(16)ST

•Stateful Switchover (SSO) —Cisco IOS Release 12.0(22)S

•Nonstop Forwarding (NSF)—Cisco IOS Release 12.0(22)S

Note For current hardware and softwarecompatibility information, refer to the Software Advisor tool at http://www.cisco.com/cgi-bin/Support/CompNav/Index.pl.

Installation Procedures

See the following sections for the configuration tasks required to run the RPR/RPR+, SSO with NSF, FSU, and SLCR features.

•Enabling the Router, page 44 (required)

•Copying an Image onto an RSP, page 44 (required)

•Setting the Config-Register Boot Variable, page 46 (optional)

•Configuring RPR and RPR+, page 46 (optional)

•Configuring a Stateful Switchover (SSO), page 49 (optional)

•Configuring Nonstop Forwarding (NSF), page 52 (optional; but SSO required)

•Performing a Fast Software Upgrade, page 60 (optional)

•Configuring SLCR, page 62 (optional)

Route Switch Processor (RSP8) Installation and Configuration Guide

	OL-4920-02	43