Unified CM event viewer logs record EndPointUnregistered alarms carrying device name, IP address, protocol, device type and a reason code, and TAC advises focusing on the reason number, MAC address and timestamp.

Checked 2026-09-24

focus on the reason number of the error message, mac address and timestamp
Vendor
Cisco
Product
Unified Communications Manager
Subsystem
alarms
Deployment
on-premises
Region
not restricted
Release range
current as of 2026-09-24
Checked
2026-09-24

Sources

Cite this note

APA

WarmTransfer. (2026, September 24). Troubleshooting Cisco IP phone registration: source note cisco-phone-registration-troubleshooting-epunreg-reason. WarmTransfer. https://warmtransfer.net/knowledge/claims/cisco-phone-registration-troubleshooting-epunreg-reason

BibTeX

@misc{warmtransfer-claim-cisco-phone-registration-troubleshooting-epunreg-reason,
  title  = {Troubleshooting Cisco IP phone registration: source note cisco-phone-registration-troubleshooting-epunreg-reason},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/cisco-phone-registration-troubleshooting-epunreg-reason},
  note   = {Source note cisco-phone-registration-troubleshooting-epunreg-reason, checked 2026-09-24}
}

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