Core Issue
By default, Cisco IP Phones are DHCP enabled. If you are not using DHCP, you need to disable DHCP on the Cisco IP Phone and manually assign it an IP address. To disable DHCP on a Cisco IP Phone, use the IP phone's keypad to program the IP phone's IP address and other network addresses.
Resolution
To resolve Cisco IP Phone registration problems when manual address configuration is used, perform these steps:
- Unlock the Cisco IP Phone by pressing **# from the keypad.
- Your Cisco IP Phone can help you resolve registration issues by using the Settings button on your IP phone and selecting Network Configuration.
Perform these steps:
- The first option to look at is Option 3 - MAC Address. Check to make sure the MAC address matches the address on the sticker on the bottom of the phone. If they do not match, use the MAC address shown in the Network Configuration when creating a device entry for this IP phone in Cisco CallManager. The MAC address for the IP phone can be checked in Cisco CallManager by selecting Device > Phone from the Cisco CallManager Administration page.
- Check Option 30 - DHCP Enable. In order to manually configure the IP addressing of your Cisco IP Phone, Option 30 must be set to No. Otherwise, the IP phone displays a
That key is not active
message when you try to edit the configuration.
- Check Option 32 - Alternate TFTP. In order to change the address of the TFTP server, this must be set to Yes. The address of the TFTP server is set with Option 8 - TFTP Server. Enter the IP address of the TFTP server the IP phone should be using. It is normally the address of the Cisco CallManager server.
- As with any other IP host, the addressing and routing must be configured. On the Cisco IP Phone these are Options 6, 7 and 9 - IP address, Subnet mask and Default router, respectively.
- The Cisco IP Phone must know where to look for its Cisco CallManagers. The IP phone attempts to open a Transmission Control Protocol (TCP) connection to all the Cisco CallManagers that are part of the CallManager Group that your IP phone is in. This is set with Option 21, 22 and 23 - Cisco CallManager 1, Cisco CallManager 2 and Cisco CallManager 3. The Cisco CallManager 1, 2 and 3 fields should show an Active and Standby server if there is more than one CallManager in the CallManager group.
- If Active and Standby does not appear, more advanced troubleshooting is required.
For background information on resolving Skinny registration issues, refer to these documents: