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config-register value not changing from 0x3122 to 0x2102

Praveen Selvam

On C4900 i am not able to change the config-register value to 0x2102. In the config mode i gave the command "config-register to 0x2102" and did a write memory. After which when i do a "show ver", it does not reflect that the config-register value will change at next reload. Ideally this line should be seen at the end of Show ver output. "Configuration register is 0x3122 (will be 0x2102 at next reload)"


Is there something that i am missing to do?


Hostname#sh ver
Cisco IOS Software, Catalyst 4500 L3 Switch Software (cat4500e-ENTSERVICESK9-M), Version 12.2(54)SG, RELEASE SOFTWARE (fc3)
Technical Support:
Copyright (c) 1986-2010 by Cisco Systems, Inc.
Compiled Sun 27-Jun-10 09:28 by prod_rel_team
Image text-base: 0x10000000, data-base: 0x12E09514

ROM: 12.2(44r)SG10
Sushi Revision 11, Tatooine Revision 141, Forerunner Revision 1.78

Hostname uptime is 2 weeks, 4 days, 23 hours, 23 minutes
System returned to ROM by reload
System restarted at 08:03:24 UTC Sat Jan 31 2015
System image file is "bootflash:cat4500e-entservicesk9-mz.122-54.SG.bin"

This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:

If you require further assistance please contact us by sending email to

cisco WS-C4900M (MPC8548) processor (revision 2) with 1048576K bytes of memory.
Processor board ID
MPC8548 CPU at 1.33GHz, Cisco Catalyst 4900M
Last reset from Reload
15 Virtual Ethernet interfaces
36 Gigabit Ethernet interfaces
16 Ten Gigabit Ethernet interfaces
511K bytes of non-volatile configuration memory.

Configuration register is 0x3122


2 Replies 2


Hi Praveen,

The config-register 0x2102 is only available on Router's.

Kind Regards.


Rising star
Rising star


With your aim to change config-register value from 0x3122 to 0x2102 you actually wish to change console speed from 57600 to 9600 bps (baud). This cannot be normally done via the "config-register" command. You can use the following CLI sequence instead:

conf t

line con 0

speed 9600



After that sequence you can see your desired line at the "sh ver" output, ie. "The configuration register is ....  and will be ... at the next reload).

Please be aware that CLI commands take effect immediately so if you are connected via the "console" port then after issuing the "speed" command you have to change your terminal emulator product (putty, hyperterminal,...) to the new speed and only after that you can continue with the configuration.

You can use also the other option to set up the configuration register from rommon of course.

Good luck!

Best regards,


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