I'm upgrading my phones (8861s) from a 10.2 firmware to 11.5. Same cluster and TFTP servers. For some reason the upgrade failed until I "Reset Security Settings" which I assume on the 88xx is the way to delete ITL.
I thought that was only required when migrating from different CUCM clusters? Why would I need to do that just for an upgrade?
And next question is, is there any way to prep that in advance or push it out? Rather than visiting every phone.
You should first make sure that the latest device for your cucm version is applied. It is a mandatory requirement as per the release notes
Yes, the error does point to some ITL/CTL issue , please check if the issue still persists after confirming the latest device pack is applied on the cucm cluster.
Bill, both the Device Packs and FW files are cop.sgn only. Naming convention for DP is something like cmterm-devicepack10.5.2.13049-1.cop.sgn whereas for FW, it is like cmterm-88xx-sip.11-0-1-11.k3.cop.sgn
Link for downloading Device Package is below. Change the CM version as per your requirements. Reboot of all the servers in cluster is mandatory after the installation of Device Package
Your understanding is correct that you need to remove the ITL files in case of moving phones between different CUCM clusters. However, there can be situation wherein certificate information had been changed on the existing cluster causing the private key to get changed and hence the phones are not able to trust the new ITL (usually happens when the certificate regeneration process had not been carried properly). Refer below in order to know the process of doing a bulk removal