I have about 40 phones that I had to delete, and then import a new BAT file for them with corrections. Now, none of the phones are registering. I noticed that when I imported the BAT file, CUCM already had IP addresses associated for the phones (I'm assuming from the previous registration). The phones are getting different IPs from the DHCP server now. I have a feeling this is why CUCM is not registering the phones. Is there a way to clear the IP address that is associated with the phones in CUCM? Thank you.
That has nothing to do with registration, you can go to a phone, change the IP, reset it, and it will register to CUCM right away, as long as it know how to get to it, and there's nothing blocking the communication.
Look at your routing and DHCP to make sure it's correct.