You can check the ip phone boot process that will help you determine the failure . List of things you can do : 1) Check if phone is getting an ip address from dhcp. 2) You can run a wireshark and check if ip phone receives network configuration , CME ip address from the tftp server or not.Beacuse at this point, the IP phone has enough information to request registration from the Cisco Unified CME router to which it is connected. The router verifies the phone's configuration against the router's running configuration. If it is correct, the phone successfully registers with Cisco Unified CME
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.