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Firmware upgrade and rollback

Verify, stage, and apply an OKTET-OS firmware image safely, with a tested rollback path if the new release misbehaves.

OKTET switches carry two firmware banks — active and backup. An upgrade writes the new image to the inactive bank and boots from it, leaving the previous, known-good image intact in the other bank. This design means a failed upgrade is recoverable without a console cable in most cases. Read this whole page before upgrading a production unit.

Before you start

  • Back up the running configuration. A configuration export is your insurance regardless of how the upgrade goes.

    show configuration | save pre-upgrade-2026-06-02.cfg

  • Read the release notes for the target version. Check specifically for any “upgrade path” requirement — some releases must be reached through an intermediate version rather than directly.

  • Confirm a maintenance window. A firmware upgrade reboots the switch. Plan for several minutes of downtime per unit.

  • Have console access available for production-critical units, in case management connectivity is lost.

1. Check the current version

show system

Note the running version and which bank is active (bank A or bank B).

2. Transfer and verify the image

Fetch the image to the switch. OKTET-OS supports HTTPS and SCP transfer:

system firmware fetch https://downloads.example.net/oktet-os-4.2.1.img

Verify the checksum before installing. Every official image is published with a SHA-256 checksum in the release notes. The switch computes it for you:

system firmware verify oktet-os-4.2.1.img

Compare the printed digest against the published value, character for character. If they do not match, delete the file and re-fetch — do not install an image that fails verification.

3. Stage to the inactive bank

Install the verified image to the inactive bank without rebooting yet:

system firmware install oktet-os-4.2.1.img

This writes the image to the backup bank and marks it as the next-boot target. The active bank — your current, working firmware — is untouched.

4. Reboot into the new image

system reboot

The switch reboots into the newly installed bank. First boot on a new image can take longer than usual while it migrates configuration. Wait for the SYS indicator to go solid before testing.

5. Validate

After the unit is up, confirm the version and check that the network is healthy:

show system
show interfaces
show log last 100

Verify the things that matter for this unit specifically — uplinks negotiated at the right speed, PoE devices powered, no error counters climbing, management reachable.

Rollback

If the new release misbehaves, roll back to the previous image still sitting in the other bank. Two paths:

If the switch is reachable, set the boot bank back and reboot:

system firmware boot-bank previous
system reboot

If the new image fails to boot or the unit is unreachable, OKTET-OS automatically falls back to the previous bank after repeated failed boots. You can also force it from the console boot menu by selecting the alternate bank during startup.

Because rollback boots an image that was already running successfully before the upgrade, recovery is fast and does not depend on re-transferring firmware. After a rollback, restore your pre-upgrade configuration export if any settings were migrated by the new release:

configure
load pre-upgrade-2026-06-02.cfg
commit
save

Upgrading a stack or multiple units

Upgrade one unit, validate it fully, and only then proceed to the next. Do not upgrade an entire row in parallel — staggering means a bad release stops at the first unit instead of taking down the whole row at once.