IP Phone is not registering and is not receiving TFTP server address

[TCC_2]

Core Issue

These are several of the issues that might cause a Cisco IP Phone not to register:

• Auto-registration is disabled on Cisco CallManager.
  
• The Cisco IP Phone is not receiving the DHCP server address.
  
• The Cisco IP Phone is not receiving the IP address, subnet mask or default router address.
  
• The Cisco IP Phone is not receiving the TFTP server.
• The Cisco IP Phone is not receiving the correct Cisco CallManager addresses.
  

Resolution

If your Cisco IP Phone is not receiving the TFTP server, perform these steps:

1. Confirm that your Cisco IP Phone is not receiving TFTP server addresses by pressing the Settings button on your IP phone and then selecting Network Configuration. For Option 8, the TFTP server shows if the Cisco IP Phone is receiving the TFTP server address. Check if it is blank or incorrect.     
2. Check the IP address you have configured in Option 150 of your DHCP server scope configuration. For more information, refer to Configuring Windows 2000 DHCP Server for Cisco CallManager.   

   Note: The same resolution applies to Option 66. However, it is usually a best practice to use Option 150. Although Option 66 allows you to specify the TFTP server IP address, TFTP server redundancy is only available by the use of Option 150.

For more background information about resolving Skinny Client registrations issues, refer to these documents:

• Troubleshooting Cisco IP Phone (7910, 7940, 7960, 12SP, and VIP30) Registration Problems with Cisco CallManager 3.x       
• Chapter 4: Skinny Client Registration from the Cisco Press book Troubleshooting Cisco IP Telephony [ISBN: 1-58705-075-7]