Before upgrading, disable High Availability on each Presence Redundancy Group and stop the Cisco Sync Agent on IM and Presence. Re-enable both afterward.

Checked 2026-09-25

Vendor
Cisco
Product
IM
Subsystem
sequencing
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-imp-ha-sync-agent. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-upgrade-planning-imp-ha-sync-agent

BibTeX

@misc{warmtransfer-claim-cucm-upgrade-planning-imp-ha-sync-agent,
  title  = {Planning a Unified CM upgrade: source note cucm-upgrade-planning-imp-ha-sync-agent},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/cucm-upgrade-planning-imp-ha-sync-agent},
  note   = {Source note cucm-upgrade-planning-imp-ha-sync-agent, checked 2026-09-25}
}

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