I have a Single Primary CUCM in production. I added another CUCM as a Secondary to the cluster. I never fully got the second CUCM licensed and configured. I removed the second CUCM from the cluster (deleted the server entry on the CM admin site) and powered off the secondary CUCM.
My primary CUCM is randomly hanging at different points in any web administration site. A packet sniff reveals that it is hammering my DNS servers for the name of the secondary CUCM, but oddly it is not the fully qualified name that I registered that CUCM with. In my initial setup, i may have attempted to register that name (non-fqdn) and deleted it. My Primary CUCM has no default domain configured.
I have rebooted the CUCM to no avail, and I am wondering if I'm missing something from the server removal process...