we’re running 2 Peplink Balance 380’s in High availability mode. Both devices run on Firmware 5.4.9. We would like to upgrade to the latest but it’s almost impossible to take both devices offline at the same time. Even the time it takes for the slave to take over isn’t preferred during business hours.
Is it save to take one offline during the evening or weekend, upgrade it to the latest firmware and bring it back online the following night and repeat the process with the other peplink? Or will the difference in firmware cause trouble with High Availability?