IP Phone 6921: firmware reset

Unanswered Question
Oct 25th, 2010


I would like to a "firmware reset" of a 6921.

For other models, I know a particular procedure (see, for example, here: http://www.cisco.com/en/US/ts/fn/620/fn62949.html), but it doesn't work with 6921s.

Who knows an analogous procedure for 6921s?

Thanks and regards.

I have this problem too.
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rob.huffman Mon, 10/25/2010 - 09:38

Hi Raziel,

Performing a Factory Reset

When you perform a factory reset of the Cisco Unified IP Phone, the following information is erased or reset to its default value:

User configuration settings—Reset to default values

Network configuration settings—Reset to default values

Call histories—Erased

Locale information—Reset to default values

Phone application—Erased (phone recovers by using the image in the inactive partition of flash to boot up).

Before you perform a factory reset, ensure that the following conditions are met:

The phone must be on a DHCP-enabled network.

A valid TFTP server must be set in DHCP option 150 or option 66 on the DHCP server.

To perform a factory reset of a phone, perform the following steps:


Step 1 Unplug the power cable from the phone and then plug it back in.

The phone begins its power-up cycle.

Step 2 While the phone is powering up, and before the Speaker button flashes on and off,

press and hold #.

Continue to hold # until each line button flashes on and off in sequence in amber.

Step 3 Release # and press 123456789*0#.

You can press a key twice in a row, but if you press the keys out of sequence, the factory reset will not take place.

After you press these keys, the line buttons on the phone flash red, and the phone goes through the factory reset process.

Do not power down the phone until it completes the factory reset process, and the main screen appears.




raziel78kain Tue, 11/02/2010 - 08:32

Dear Mr. Huffman,

thanks for the answer, but we were looking for a procedure to completely erase the firmware on the phone and to download the firmware from a TFTP server, whatever it is.


Silas Taylor Thu, 09/20/2012 - 03:51

Hi Rob,

This proceedure works for 7942's and 7962's but does not appear to work for 6921's.




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