I recently had to upgrade a Cisco router to a new firmware version, so I thought I’d write up a quick how-to guide.
Prerequisites:
- Download the new flash version from Cisco (you need a valid Cisco login)
- TFTP the firmware to the Cisco device
- Connect to the Cisco device using a console cable (highly recommended!
1. Log into the router
2. Elevate to enable
enable
<password>
3. Check to see if the flash is in the correct location
dir flash:
4. Enter configuration terminal
config term
5. Disable current flash
no boot system
6. Specify flash file
boot system flash: <fullfilenameplusextension>
7. Exit out of configuration terminal
exit
8. Display the version
show version
If the last digit in the configuration register is 0 or 1 the n go to next step however if the last digit in the configuration register is between 2 and F then proceed to step 12
9. Enter configuration terminal
config term
10. Run config-register command
config-register 0x2102
11. Exit out of configuration terminal
exit
12. Copy the running to startup
copy run start
13. Restart the Cisco device
reload
When prompted to save the configuration, enter no
When prompted to confirm and reload, enter yes
If the router reboots and then reboots again straight away, it has not worked and has reverted back to the last firmware version
If it simply reboots, log in and check the version
show version
Should you have any questions, comments or suggestions, please don’t hesitate to comment below. If you like what you have read, please share it on your favourite social media medium.