Cisco Catalyst 4500 Series Software Configuration Guide

8-2
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 8 Configuring the Cisco IOS XE In Service Software Upgrade Process
Prerequisites to Performing ISSU
Related Documents
Prerequisites to Performing ISSU
Before performing ISSU, you must meet these prerequisites:
• A permanent “ISSU barrier" exists between pre-IOS XE 3.6.0E and IOS XE 3.6.0 releases: ISSU is
supported between versions on the same side of the barrier but it is not supported between versions
on opposite sides.
Note This restriction applies to Catalyst 4500X in a VSS, as well as to Supervisor Engine 7E,
Supervisor Engine 7LE, and Supervisor Engine 8E in a VSS or in a redundant chassis.
Four scenarios will illustrate the restriction:
If you are running a release prior to IOS XE 3.6.0E (3.5.1E, for example), you cannot perform
an ISSU upgrade to IOS XE 3.6.0E.
If you are running IOS XE 3.6.0E, you cannot perform an ISSU downgrade to IOS XE 3.5.0E.
If you are running IOS XE 3.6.0E, you can perform an ISSU upgrade to IOS XE 3.6.1E (when
released).
If you are running a release after IOS XE 3.6.0E (for example, 3.7.0, when released), you cannot
perform an ISSU downgrade to IOS XE 3.5.0E.
• The type of the existing and target image must match. You cannot upgrade from a Universal Lite
image to a Universal image (and vice versa) without experiencing several minutes of traffic loss. The
same restriction applies between crypto and non-crypto images.
• The active and the standby supervisor engines must have the same supervisor engine hardware (same
model, same memory, and so on).
• The new and old Cisco IOS XE software images must be loaded into the file systems (bootflash, SD
card, or USB) of both the active and the standby supervisor engines before you begin the ISSU
process.
The old software image should be available either in bootflash, SD card, or USB and the system
should have been booted from one of these locations because the boot variable must be changed
before the ISSU process starts.
Related Topic Document Title
Performing ISSU Cisco IOS Software: Guide to Performing In Service Software
Upgrades
Information about Cisco Nonstop Forwarding Cisco Nonstop Forwarding
http://www.cisco.com/en/US/docs/ios/12_2s/feature/guide/fsnsf20s.
html
Information about Stateful Switchover Stateful Switchover
http://www.cisco.com/en/US/docs/ios/12_0s/feature/guide/sso120s.
html

Cisco Catalyst 4500 Series Specifications

General

Series	Catalyst 4500 Series
Category	Switch
Layer Support	Layer 2, Layer 3
Form Factor	Modular chassis
Stackable	No
Chassis Slots	3, 6, 7, 10
Power Supply Options	AC, DC
Redundancy	Power supply, Supervisor engine
Network Management	Cisco IOS Software CLI, SNMP, Cisco Prime Infrastructure
Features	Security, QoS
Port Density	Up to 384 ports per chassis
Security Features	802.1X, ACLs, DHCP Snooping, Dynamic ARP Inspection, IP Source Guard
Supervisor Engine	8-E