In-Service Software Upgrade (ISSU)
Information About In-Service Software Upgrade (ISSU)
ISSU is a process that upgrades an image to another image on a device while the network continues to forward packets. ISSU helps network administrators avoid a network outage when performing a software upgrade. ISSU is supported in install mode.
Note |
Refer to the release notes and check the list of unsupported commands across releases before initiating an ISSU upgrade, as the upgrade may fail when unsupported commands are present. |
ISSU Support between Releases
EM: extended maintenance
SM: standard maintenance
For information on IOS XE Software Lifecycle, see the following link: https://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/ios-xe-16/bulletin-c25-2378701.html
Supported Scenarios |
Unsupported Scenarios |
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Release Support Matrix
The following tables show ISSU support within the same EM.
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For Cisco Catalyst 9800 Series Wireless Controllers, ISSU support starts from Cisco IOS XE Amsterdam 17.3.1.
For a comprehensive list of supported ISSU upgrade matrices across multiple releases for the Cisco Catalyst 9800 Series Wireless Controllers, see the following link: https://www.cisco.com/c/dam/td-xml/en_us/wireless/vewlc/issu/ISSU.xlsx
Cisco Catalyst 9800 Series Wireless Controllers
From/To |
17.3.1 |
17.3.2a |
17.3.3 |
17.3.4 |
17.3.4c |
17.3.5 |
17.3.5a |
17.3.5b |
17.3.6 |
17.3.7 |
17.3.8 |
17.3.1 |
— |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
17.3.2a |
x |
— |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
17.3.3 |
x |
x |
— |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
17.3.4 |
x |
x |
x |
— |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
17.3.4c |
x |
x |
x |
x |
— |
✓ |
✓ |
✓ |
✓ |
✓ |
✓ |
17.3.5 |
x |
x |
x |
x |
x |
— |
✓ |
✓ |
✓ |
✓ |
✓ |
17.3.5a |
x |
x |
x |
x |
x |
x |
— |
✓ |
✓ |
✓ |
✓ |
17.3.5b |
x |
x |
x |
x |
x |
x |
x |
— |
✓ |
✓ |
✓ |
17.3.6 |
x |
x |
x |
x |
x |
x |
x |
x |
— |
✓ |
✓ |
17.3.7 |
x |
x |
x |
x |
x |
x |
x |
x |
x |
— |
✓ |
17.3.8 |
x |
x |
x |
x |
x |
x |
x |
x |
x |
x |
— |
From/To |
17.6.1 |
17.6.2 |
17.6.3 |
17.6.4 |
17.6.5 |
17.6.6 |
17.6.1 |
— |
✓ |
✓ |
✓ |
✓ |
✓ |
17.6.2 |
x |
— |
✓ |
✓ |
✓ |
✓ |
17.6.3 |
x |
x |
— |
✓ |
✓ |
✓ |
17.6.4 |
x |
x |
x |
— |
✓ |
✓ |
17.6.5 |
x |
x |
x |
x |
— |
✓ |
17.6.6 |
x |
x |
x |
x |
x |
— |
From/To |
17.9.1 |
17.9.2 |
17.9.3 |
17.9.4 |
17.9.1 |
— |
✓ |
✓ |
✓ |
17.9.2 |
x |
— |
✓ |
✓ |
17.9.3 |
x |
x |
— |
✓ |
17.9.4 |
x |
x |
x |
— |
How to Configure ISSU
To configure ISSU, see the In-Service Software Upgrade chapter of the configuration guide:
Additional References for ISSU
Related Topic |
Document Title |
---|---|
Software Configuration Guides |
Cisco Catalyst 9800 Series Wireless Controller Software Configuration Guide |
Release Notes |
Release Notes for Cisco Catalyst 9800 Series Wireless Controller |
Command References |
Cisco Catalyst 9800 Series Wireless Controller Command Reference |
Troubleshooting TechNotes |