Cisco Cisco IOS Software Release 12.2(33)SRE
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Cisco IOS In Service Software Upgrade Process
First Published: March 16, 2006
Last Updated: June 4, 2007
Last Updated: June 4, 2007
The Cisco IOS In Service Software Upgrade (ISSU) process allows Cisco IOS software to be updated or
otherwise modified while packet forwarding continues. In most networks, planned software upgrades are
a significant cause of downtime. ISSU allows Cisco IOS software to be modified while packet
forwarding continues, which increases network availability and reduces downtime caused by planned
software upgrades. This document provides information about ISSU concepts and describes the steps
taken to perform ISSU in a system.
otherwise modified while packet forwarding continues. In most networks, planned software upgrades are
a significant cause of downtime. ISSU allows Cisco IOS software to be modified while packet
forwarding continues, which increases network availability and reduces downtime caused by planned
software upgrades. This document provides information about ISSU concepts and describes the steps
taken to perform ISSU in a system.
This document also provides information about Enhanced Fast Software Upgrade (eFSU) concepts. For
further information about eFSU, see Enhanced Fast Software Upgrade on the Cisco 7600 Series Router,
Release 12.2(33)SRB1.
further information about eFSU, see Enhanced Fast Software Upgrade on the Cisco 7600 Series Router,
Release 12.2(33)SRB1.
Finding Feature Information in This Module
Your Cisco IOS software release may not support all of the features documented in this module. To reach
links to specific feature documentation in this module and to see a list of the releases in which each feature is
supported, refer to
links to specific feature documentation in this module and to see a list of the releases in which each feature is
supported, refer to
.
Finding Support Information for Platforms and Cisco IOS and Catalyst OS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS
software image support. To access Cisco Feature Navigator, go to
software image support. To access Cisco Feature Navigator, go to
. An
account on Cisco.com is not required.
lists the release history for this feature.
Use Cisco Feature Navigator to find information about platform support and software image support.
Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images
support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to
Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images
support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to
. An account on Cisco.com is not required.
Note
lists only the Cisco IOS software release that introduced support for a given feature in a given
Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS
software release train also support that feature.
software release train also support that feature.