"Auth Fail" on Cisco VoIP Phone during firmware upgrade / downgrade

I manually changed the firmware version on a Cisco 7965 VoIP phone the other day and ran into a strange error message that turned out to be the result of a typo. When the firmware upgrade screen came up on the phone, the upgrade didn't progress and one of the boxes said "Auth Fail". It turns out that I had accidentally told the 7965 to use the firmware from a 7962/7942 phone.

The firmware for a 7945 or 7965 starts with SCCP45 or SIP45, depending on whether the phone is Skinny or SIP. For example, SCCP45.8-5-3S is the current version of the 7965.

The firmware for a 7942 or 7962 starts with a SCCP42 or SIP42. For example, SCCP42.8-4-3S is the version that was selected for the software downgrade.

The 7965 obviously didn't like the 7942/7962 software, and the "Auth Fail" message was the result.

Models and versions: Cisco CP-7965G VoIP phone with firmware SCCP42.8-5-3S, Cisco Unified Communications Manager (CallManager) 6.1.5.10000-10

WARNING: This worked for me, but there is no guarantee that it will work for you. Please understand what you're doing before you change anything.

"Pass Limit" error message on Cisco VoIP Phone

I recently plugged in some Cisco 7962 VoIP phones to upgrade their firmware and prepare them for deployment. After the firmware upgrade, a few of the phones were missing the auto-registered directory number (DN) and there was a "Pass Limit" message at the bottom left corner of the screen.

Solution #2 on this page showed me that the problem was related to unassigned DNs. To resolve the issue, I:

1. Unplugged the phone
2. In the Cisco Unified CM Administration site, went to "Device" -> "Phone".
3. "Find Phone where Device Name begins with SEP". I replaced with the hardware address of the phone that wasn't auto-registering.
4. Clicked the "Find" button.
5. Selected the box to the left of the phone.
6. Clicked "Delete Selected".
7. Plugged the phone back in and it auto-registered normally.

To prevent this from happening, I should clear out my unassigned DNs periodically:

1. In the Cisco Unified CM Administration site, go to "Call Routing" -> "Route Plan Report".
2. "Find Unassigned DN Route Plan Report where Pattern/Directory Number begins with ". just means leave that field blank.
3. Click the "Find" button.
4. Click "Delete All Found Items" in the "Route Plan Report" menu bar.

Models and versions: Cisco CP-7962G VoIP phone with firmware SCCP42.8-5-3S, Cisco Unified Communications Manager (CallManager) 6.1.5.10000-10

WARNING: This worked for me, but there is no guarantee that it will work for you. Please understand what you're doing before you change anything.