How to upgrade Cisco IOS from Serial Port
In this topic, i will show how to upgrade Cisco IOS from the Serial Port using a console cable and Hyper Terminal without network connectivity (that would be needed for TFTP, in example). We will be using a 2960X for the testing and we will also learn how to get into rommon mode when you are not physically close to the switch.
Pre-Req
- Hyper Terminal (or similar);
- Cisco Switch;
- Console Cable;
- IOS Boot Image;
- Running Config Backup (if needed).
Step-By-Step
- Connect PC to the Switch using the console cable;
- Connect the switch to the power and boot it up;
- Create a new connection in HyperTerminal and set the transfer rate to 9600;
- Issue the following commands in order to get the 2960X in rommon mode:
- enable
- conf t
- boot manual
- boot enable-break
- end
- write
- reload
- (press enter to confirm)
- When the switch reloads, it will be in rommon mode;
- Issue the following command in order to upload the .bin faster:
- Reconnect HyperTerminal to match the transfer speed rate from the switch. This time, select 57600 as your transfer rate;
- Issue the following command for the switch to wait for the file:
- copy xmodem: flash:c2960x-universalk9-mz.152-2.E5.bin
- In this case, "c2960x-universalk9-mz.152-2.E5.bin" is the full name of the binary file that i have to upload.
- You will see a line "Begin the Xmodem or Xmodem-1K transfer now...";
- In your HyperTerminal window, click Transfer and then, send file (The transfer may take hours, depending on the file size);
- Select the file using the Browse Button and change the protocol to Xmodem;
- Click Send;
- A progress bar will show up and you should wait until the file is transfered;
- Issue the following command in order to ensure that you have the file in place:
- dir flash:
- You should be able to see the file (in my case, "c2960x-universalk9-mz.152-2.E5.bin")
- When it is done, issue the following command to turn the transfer rate back to 9600:
- Reconnect your HyperTerminal using transfer rate 9600
- Issue the following command to bring select your new boot image and bring your switch back to life:
- boot flash:/c2960x-universalk9-mz.152-2.E5.bin (put the new file name there).
- Wait for the switch to boot;
- enable
- conf t
- boot system flash:/c2960x-universalk9-mz.152-2.E5.bin (put the new file name there).
- no boot manual
- no boot enable-break
- write
Possible Issues
- If your switch did not save the previous BAUD rate when you did in rommon, log back on it using your serial cable and try to make it work using 57600 or 9600. Once you log in, do:
enable
conf t
lin con 0
speed 9600
end
copy run start
write
Conclusion
If you followed correctly the steps above, your switch will now have the new version installed. You can know see it by running the command "show version".
