On Cisco IP Phone 8800 series, if the ITL authenticates but other configuration files do not, the documented cause is that the configuration file is not signed by the matching certificate in the phone's trust list.
Checked 2026-10-01
- Vendor
- Cisco
- Product
- IP Phone 8800 Series
- Subsystem
- Phone security
- Deployment
- on-premises
- Region
- not restricted
- Release range
- current as of 2026-10-01
- Checked
- 2026-10-01
Sources
- Cisco IP Phone 8800 Series Administration Guide for Cisco Unified Communications Manager - Troubleshooting — Cisco Systems · tier 2 current vendor documentation · Cisco IP Phone Security Problems > CTL File Problems > ITL File Authenticates but Other Configuration Files Do Not Authenticate
Cite this note
APA
WarmTransfer. (2026, October 1). Troubleshooting phone trust and ITL failures in Unified CM: source note cucm-itl-trust-troubleshooting-p8800-itl-ok-config-fails. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-itl-trust-troubleshooting-p8800-itl-ok-config-fails
BibTeX
@misc{warmtransfer-claim-cucm-itl-trust-troubleshooting-p8800-itl-ok-config-fails,
title = {Troubleshooting phone trust and ITL failures in Unified CM: source note cucm-itl-trust-troubleshooting-p8800-itl-ok-config-fails},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cucm-itl-trust-troubleshooting-p8800-itl-ok-config-fails},
note = {Source note cucm-itl-trust-troubleshooting-p8800-itl-ok-config-fails, checked 2026-10-01}
}