Why would firmware update fail in device HA mode?

Zyxel_Cooldia

Question

I am doing firmware upgrade on active device. It seems only stand-by device update successfully, but active device stays at the same firmware version. Why would firmware update fail in device HA mode?

Answer

It could be caused by firmware update check timeout mechanism.
By default, the firmware update check timeout is 1800 seconds.
When we update firmware in device HA mode, firmware would update to stand-by device first, once stand-by device update firmware and reboot successfully, active device will continue to update firmware.
Assume that if stand-by device have complicated settings, it may need take long time to reboot and apply startup configuration file. Once it over 1800 seconds, active would not update firmware to avoid network service down.
In this case, we can enlarge time by cli below to avoid firmware update fail on active device.

CLI

Router(config)# device-ha2 firmware-update check-timeout <1~3600>