In-service software upgrade (ISSU)
An In-Service Software upgrade (ISSU) is a wireless controller procedure that
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upgrades the controller software image to a later release while the network continues to forward packets
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enables administrators to avoid network outages during software upgrades, and
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allows cold patches to be applied without impacting the active network.
ISSU is supported only on these Cisco Catalyst 9800 Series Wireless Controllers. It supports only upgrade operations.
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Cisco Catalyst 9800-80 Wireless Controller
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Cisco Catalyst 9800-40 Wireless Controller
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Cisco Catalyst 9800-L Wireless Controller
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Cisco Catalyst 9800-CL Wireless Controller (Private Cloud)
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Cisco Wireless 9800M Wireless Controller
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Cisco Wireless 9800H1/H2 Wireless Controller
High-Level Workflow of ISSU
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Onboard the controller software image to the flash memory.
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Download the AP image to the AP.
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Install the controller software image.
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Commit the changes.
|
Feature Name |
Release Information |
Feature Description |
|---|---|---|
|
In-Service Software Upgrade (ISSU) |
Cisco IOS XE 17.1.1s |
This feature 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. |

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