The firmware is released in two formats: KerOS and Liveburner. These have very different behavior, so please use the appropriate file before updating, see the difference in upgrade process section.

To upgrade the system from KerOS version 4.3.3 to KerOS version 5.x the use of a liveburner is mandatory. Two possibilities are available:

• Upgrade with a custom liveburner. It allows to keep some elements like gateway configuration. To use a custom liveburner, please refer to the dedicated page: Major version upgrade with a custom liveburner
• Upgrade with a regular liveburner (erasing the whole partition to reinstall the firmware). Use the liveburner provided in the Wirnet gateways resources page and the upgrade process below.

The upgrade from KerOS version 3.x to KerOS version 4.1 directly is not recommended by Kerlink. To do so, it must be done in 2 steps:

1. Upgrade to KerOS version 4.0 using a liveburner
2. Upgrade from KerOS version 4.0 to KerOS version 4.1 using a KerOS package

To upgrade the system from KerOS version 3.x to KerOS version 4.0 the use of a liveburner is mandatory. Two possibilities are available:

• Upgrade with a custom liveburner. It allows to keep some elements like gateway configuration. To build a custom liveburner, please refer to the dedicated page: Upgrade from KerOS version 3.x to 4.0
• Upgrade with a regular liveburner (erasing the whole partition to reinstall the firmware). Use the liveburner provided in the Upgrade from KerOS version 3.x to 4.0 page and the upgrade process below.

Upgrade using a KerOS package (i.e. keros_4.X.Y_klk-lpbs-signed.ipk file) could be done only with the same major version.
Example:

• Upgrade from Keros 4.X.X to KerOS 4.Y.Y is possible with a KerOS package (same major version)
• Upgrade from Keros 4.X.X to KerOS 5.X.X is not possible with a KerOS package (major version is different)

The upgrade will install the new KerOS firmware with some consequences on the data:

• User partition files will be preserved.
• Passwords will be preserved.
• The stock restore version will not be updated.
• RootFS modifications will NOT be kept except files indicated in sysupgrade configuration files

The upgrade process itself is the following sequence:

1. Backup files indicated in configuration (system files and software/customer defined files).
2. Remove hotfix packages.
3. Upgrade the system itself.
4. Restore sysupgrade files ⇒ will override new firmware files!!

To upgrade your system, follow the software update process. Information here.