Following commands can help you to diagnose your ShoreTel IP Phone issue.
ping “xxx.xxx.xxx.xxx” - Enter the Phone IP address. You can get the ip address from the ShoreTel Director.
printsysInfo - Shows a lot of system info for the phone. This will also allow you to vie the MAC Address.
reboot - This command can help you to Reboots the phone from command line.
You can also reboot the phone from the ShoreTel Director.
You can also reboot ShoreTel Phone by pressing MUTE Button and then dialing 4696 # from your ShoreTel Phone.