Firmware reverting when disconnected

[keynkshfo94]

Hey all! Fairly new IP Phone person here... I am in the process of provisioning a refurbished 8865 without CUCM for Zoom Phone. I attempted to update the firmware from the 2015 version (blue) using TFTP. The files loaded and the upgrade worked. The phone loaded into the 2024 firmware. However, when I disable to TFTP server or disconnect the phone, it restarts and reverts back to the old firmware. Does anyone know why that may be?

[Jonny Bacoz]

It sounds like the Cisco 8865 IP Phone is temporarily loading the new firmware via TFTP but failing to write the update permanently to its internal storage. This often happens if the phone is set to boot from the network or if the firmware isn't being properly saved after the upgrade. Ensure that the phone's configuration allows it to boot from local memory rather than relying on TFTP. Also, check if there is a specific option or command within the phone's menu to apply and save the firmware update permanently. Make sure the TFTP server settings on the phone are configured correctly so the phone doesn't default back to the older firmware upon reboot. If the issue persists, refer to the phone's manual for details on permanent firmware installation or reach out to Cisco support for guidance.

[Maren Mahoney]

The 8865 phones have a flash that is big enough to hold two different firmware. Downloading a new firmware to the phone does just that, downloads it into flash. If you had CUCM you can then tell the phone which of the two firmware to use. As you are not using CUCM, you would need to try one of two things.

First, you could perform a factory reset on the phone (which wipes out all firmware in the writable partition of the flash). This will cause the phone to use the Factory Firmware in the non-writable partition. The phone would automatically use the firmware downloaded to the writeable partition, unless that firmware is older than the factory firmware.

Second, you could get a console cable and access the CLI on the phone. Using the command line, you can tell the phone which firmware to use. I have not done this in a number of years, so you'd have to research the correct pinout for the cable, any password that might be on the phone, and the exact command sequence. But it is doable.

Maren