Details the supported upgrade modes for Cisco Catalyst 9000 series switches, including bundle and install modes, in-service software upgrade, and extended fast software upgrade.
This topic explains the different upgrade modes available for Cisco Catalyst 9000 series switches to help you choose and implement the appropriate upgrade method for your deployment scenario.
Bundle mode
Bundle mode boots the switch directly from the monolithic Cisco IOS XE .bin image, with packages extracted to RAM at boot. The boot variable points directly to the .bin file. For stack, dual-supervisor, or StackWise Virtual scenarios, copy the image to every required flash location before reloading.
Install mode
Install mode expands the .bin image into packages and uses packages.conf to identify the package set. The boot variable must point to packages.conf, and the install workflow can add, activate, commit, abort, and roll back versions.
In-service software upgrade
In-service software upgrade (ISSU) upgrades the software while the system continues forwarding traffic. It is supported only in install mode on eligible HA designs such as StackWise Virtual or dual-supervisor systems.
Extended fast software upgrade
Extended fast software upgrade (xFSU) for Catalyst 9300 stackable access switches, designed to reduce upgrade downtime by completing as much of the upgrade as possible before the data plane is taken offline.