Make no configuration changes during the upgrade. Cisco says changes made then are overwritten, and that includes password changes, LDAP synchronisation and automated jobs.

Checked 2026-09-25

Stop all configuration tasks. Don't make any configuration changes during the upgrade.
Vendor
Cisco
Product
Unified Communications Manager
Subsystem
change freeze
Deployment
on-premises
Region
not restricted
Release range
Release 15 and SUs as of 2026-09-25
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). Planning a Unified CM upgrade: source note cucm-upgrade-planning-no-config-during-upgrade. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-upgrade-planning-no-config-during-upgrade

BibTeX

@misc{warmtransfer-claim-cucm-upgrade-planning-no-config-during-upgrade,
  title  = {Planning a Unified CM upgrade: source note cucm-upgrade-planning-no-config-during-upgrade},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/cucm-upgrade-planning-no-config-during-upgrade},
  note   = {Source note cucm-upgrade-planning-no-config-during-upgrade, checked 2026-09-25}
}

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