I recently accidentally messed up a Cisco 3750 switch while upgrading the firmware on it. I ended up with a non-booting switch with the typical fast flashing SYST light. After finding a computer old enough with a serial port I got to uploading the .bin image, but the at the default baud rate of 9600 the 12M or so bin file would have take quite some time. After searching on google I found out that the following IOS command would set a higher baud rate.

set BAUD 115200

Still not fast enough, but an improvement. Some people have suggested using tftpdnld in rommon mode, but this was fast enough that I didn’t want to deal with rommon.

Remember to reset the baud rate after you are done.

set BAUD 9600
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