Cisco Unified Communications Manager (CallManager)

Solving DHCP and TFTP Problems with Windows 2000 and CallManager IP Phones

Document ID: 13943

Updated: May 22, 2007



This document addresses the common problems, symptoms and resolutions related to the Dynamic Host Configuration Protocol. (DHCP) server.



There are no specific requirements for this document.

Components Used

This document is not restricted to specific software and hardware versions.


Refer to Cisco Technical Tips Conventions for more information on document conventions.

Cisco IP Phone Cannot Identify IP Address


The Cisco IP Phone cannot identify the IP address of the TFTP server.


  • The Cisco IP Phone displays this information:

    Copyright 1999 L2.02
    Cisco Systems, Inc.
  • The Cisco IP Phone does not register with Cisco CallManager.

  • When the IP phone configuration is displayed, the TFTP address field shows, or a wrong IP address. This can be done when you press * # # # # # # # #.


This issue can be addressed with this procedure.

  1. Make sure these options are on the DHCP server:

    • Option 003: Default Gateway

    • Option 006: Domain Name System. (DNS) Servers

    • Option 015: Domain Name

    • Option 066: Boot Server Hostname (TFTP server) (Not Mandatory)

  2. Define option 150 if the TFTP server does not have an entry in the DNS server.

  3. Add a custom TFTP server. In order to do this, complete these steps:

    1. Right-click the DHCP server and select Set Predefined Options.

    2. Click Add.

    3. Type TFTP Server IP address in the Name field.

    4. Choose IP address in the data type list.

    5. Type 150 in the Identifier box and click OK.

    6. Select Option 150 from the Option Name under the Value section, type the IP address of the TFTP Server in the DHCP Options Default Values window, and click OK.

  4. Add Option 150 in Cisco Network Registrar.

    1. Select the DHCP cluster.

    2. Go to the Advanced tab and click on Custom Options.

    3. Click Add.

    4. Enter Option number 150 and the Option Data Type of IP address. Click OK.

    5. Go to the Policies tab and select your policy.

    6. Add the custom Option 150.

    7. Enter the TFTP IP address under IP address array.

    8. Click on Always send to DHCP clients.

    9. Enter Yes to commit the changes to the database.

Contact Failure Between the Cisco IP Phone and DHCP Server


The Cisco IP Phone fails to contact the DHCP server.


  • The Cisco IP Phone displays this information:

    Copyright 1999 L2.02
    Cisco Systems, Inc.
  • The Cisco IP Phone does not register with Cisco CallManager.

  • The Status Code on the phone (press * *) returns a DHCP problem.

TFTPRequestNotFound Error in RTMT

The TFTP server sends a request for all configuration files, phone loads, audio files, and so forth. Even when the phone boots up for the first time with the new TFTP server, it sends a TFTPRequestNotFound error message because it is in the process of creating the file for the first time.

The TFTPRequestNotFound error message always shows some failed requests for the IP phone that have registered for the first time, or for IP phones that are deleted, but have their CNF files in the TFTP server. You can solve this when you disable the caching of the startup and configuration files and then recreate them.

  1. From the CallManager Administration page, choose Service > Service Parameters.

  2. Select your TFTP server from the drop-down list, select Cisco TFTP service, click the Advanced tab and then set these parameters:

    • Set Build CNF Files to Build All.

    • Set Enable Caching of Constant and Bin Files at Startup to False.

    • Set Enable Caching of Configuration Files to False.


  3. Click on Update and restart the TFTP service.

    Note: This recreates the configuration files and might take a long time if a large number of devices exist on the network.

Related Information

Updated: May 22, 2007
Document ID: 13943