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3750 recovery BAUD setting

cweatherford
Level 1
Level 1

So I had to format flash and recover. I did the quicker way by using set BAUD 115200...once the .bin was across I forgot to set the baud back to 9600. I have followed instructions: go back to switch: set BAUD 9600 then reset. also tried the unset command. problem is it always comes back up with a BAUD of 115200. Can someone tell me wahat I am doing wrong? Will I have to label 1 switch as 115200?

TIA!

49 Replies 49

Thanks Peter, that worked for me :)


-If I helped you somehow, please, rate it as useful.-

Five years old advice and still a lot helpful :) . Thanks Peter :)

There is also miss

set baud 9600

I´ve founded with this command:

set

Peter,

Thanks for ur commands and it helped to recover 3750-24TS-E model from 115200 to 9600

Thanga

Hello Thangaraj,

Did it really help??? Man, I would be so glad if it did!

Best regards,

Peter

Thanga,

Please let us know if you tried Peters instructions and if they worked.

Thanks,

Chad

Have you tried "unset BAUD"?

I've ROMmon a 3750G a month ago and set the baud to 115200.  I use "unset BAUD" and the baud rate went back to default 9600.

NOTE:  The command has to be in the correct syntax:  "unset" in lower case and "BAUD" in upper case.

Hi Leo,

That was my original thought as well, but if you check the very first post in this thread, the original poster writes:

I have followed instructions: go back to switch: set BAUD 9600 then  reset. also tried the unset command. problem is it always comes back up  with a BAUD of 115200.

So I thought I won't be asking about the unset command anymore - but anyway, a good point.

Best regards,

Peter

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Posting


I noticed that in the original post too, but as I wrote earlier, don't recall it taking a lot of commands, as Peter described, to get it back to 9600, but recall the documented procedure didn't work.  The key difference might be whether IOS is booted before or after rommon is reverted to 9600.  Leo, do you recall which was the case for you?

I've been trying to remember more about that incident, and I think I remember, what I encountered was after booting into the loaded IOS, without first resetting the baud, was I could reset (or unset?) the baud back to 9600, so switch would boot back into rommon at 9600 but when the IOS loaded the console port would reset to 115200.  (If this memory is correct, it was extremely annoying since baud rate would change during the boot process.)  Is there a way to change console baud rate in 3750 IOS?

The key difference might be whether IOS is booted before or after rommon is reverted to 9600.  Leo, do you recall which was the case for you?

Nope.  I've never seen an "unset BAUD" never worked before.  And to tell you frankly, I've broken alot of IOS (loaded the wrong one, erased the right one and/or formated the flash) and I've yet to see the "unset BAUD" fail me.

Is there a way to change console baud rate in 3750 IOS?

I did a ROMmon upgrade of a 3750 4 months back.  I made sure my baud rate was 115200 because I loaded the 12.2(25)SEE IOS in about 45-50 minutes.  After that, I just did an "unset BAUD" and it reverted to default 6900.

cool!!!

it is weird that i found 6-7 TAC cases describing the issue and in at least 2 customers tried the reset procedure suggested by Peter with no success. I wonder if they did not follow it the right way or some other underlying hw issue popped up.

Riccardo,

My suggested procedure involves rewrite of the boot sector contents - something generally not described in "popular literature". Did the TAC cases use the set_bs and set_param commands?

Best regards,

Peter

yes, i found a case where the bu suggested that... not completely sure about the way the customer tried that.

maybe he just said he did it while he did not as he wanted the switch replaced

I know that I forgot to do the unset before I rebooted. Leo, did you say you had used the unset either way?

did you say you had used the unset either way?

That is correct.  I have used the "unset BAUD" before a reboot (enter the command, hit enter, change the baud settings of my console client and enter "boot") and I've done this AFTER a reboot (enter "boot", go "Oooops!  ", enter the "unset BOOT" when the appliance finally boots up, change the baud settings).  Either way, doesn't make any difference.

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