Tuesday, April 6, 2010

Probably the most useful thing I have found in ages

Hi Guys

I just had to point this out to everyone I can find,


Its a field notice from cisco on how to TRULY factory reset their phones, I am talking, the phone has 0 firmware when you run this, its literally a dumb device and the screen does not turn on
BUT it sends out a DHCP and goes off and tries to find its upgrade software. This is NOT the same as your standard reset sequence (hold # plug phone in press 1 2 3 4 5 6 7 8 9 * 0 #)

So if you ever run across a situation where you are just SURE a phone is bricked. give this a try

your best bet is to run a debug tftp or somehow or another debug your TFTP so you can see if the phone is trying to get the TFTP files it should be or not.

I hope this helps someone out there

Just in case anything every happens to that cisco site, i have reposted the sequence here:

(key sequence is: 3491672850*#)
  1. Make sure your phones are on a network with a valid DHCP server.

  2. Make sure the DHCP server on this network has a valid Option 150 setting pointing to a valid Cisco TFTP server.

  3. Make sure you have a valid term11.default.loads file from load 8.2(2)SR1 or higher on the TFTP server that is referenced in Option 150.

  4. Make sure you have all other needed image files present on this same TFTP server. * See note below.

  5. Change the timing on the network - the problem is related to timing. Toggle switch port settings between "Auto" and "100Mbps." On a Cisco switch the command to toggle the switch port switch:

    interface range fastethernet
    set speed 100
    set duplex full

    Wait 10 minutes, or until all the phones have been updated, then issue the following command if desired to return to original configuration:

    interface range fastethernet
    set speed auto

    set duplex auto

    Ensure that items 1 through 5 have been completed. If performing these five steps does not resolve the issue, continue with the remaining steps.

  7. Pull power on the phone (even if power is PoE).

  8. Hold down the # key on the phone.

  9. Continue holding down the # key and re-apply power.

  10. While still holding the # key wait for the Message Waiting Indicator (MWI) light on the handset to start flashing.

  11. Once the MWI light is flashing, release the # key and enter the following sequence exactly on the keypad:


    Once this sequence has been entered on the IP Phone, if all the network criteria above have been met, it should begin its recovery process. This process can take up to 15 minutes to finish. The phone may appear to be doing nothing during this time. However, if the phone does not recover after 20 minutes then it is possible that the recovery is stuck. In this case, re-examine your network and verify that steps 1-4 are in place, then re-issue the factory reset sequence.

* Note: The factory reset sequence is a way for a phone to clear flash and still upload to a valid firmware image. This is facilitated by the termxx.default.loads file, but requires that the image files listed in the termxx.default.loads file are available in TFTP for the phone to download. Open the termxx.default.loads file in any text editor. This loads file is essentially just a packing list showing all the OS and application files the phone needs to function. The files include a cnu, cvm, dsp, app and jar files. Please make sure that these files as listed in the termxx.default.loads file are in TFTP. ("xx" will be either "06" for the CP-7906G model, or "11" for the CP-7911G model.)


  1. That was one of the most useful things I've heard in ages! :)

  2. really helped!!!
    thank you

  3. Great find . This really helped. Thank you

  4. Really helpful when I thought I had bricked my 7975. You don't get the MWI indicator on the 7975 just wait until the 8 line leds have sequenced once and then enter the full reset code. I use the TFTPD32 ver 3.23 as my TFTP server with the phone loads loded and the IP address set to on my laptop. The laptop is connected to the phone with a crossover cable and the TFTPD32 DHCP server set to give out addresses from option 150 and most importantly the additional option of 0x0101A8.

    Thank you.

    Martin H