NEED HELP: NO KNOWN BAUD RATE WILL WORK WITH MY CATALYST 2950

MOMO · ‎10-07-2017

Hi guys,

Need help on this.

I've been trying to access the CLI of my c2950 switch but to no success. All I can see is garbage on my emulator. I already tried all baud rate settings available; also tried to break the process; tried using Putty and TeraTerm - and still the same result.

When I turn on the c2950, I know that it boots properly (well, i think) because of the volume of characters show on my emulator. I just couldnt read it. I'm not sure thought if this switch is configured.

Note: I'm trying to access it using console port.

marce1000 · ‎10-08-2017

- Check ALL of these settings on your terminal emulator :

Bits per sec    :  9600 
Data bits       :     8 
Parity          :  none 
Stop bits       :     1 
Flow control    :  none

M.

-- Each morning when I wake up and look into the mirror I always say ' Why am I so brilliant ? '
When the mirror will then always repond to me with ' The only thing that exceeds your brilliance is your beauty! '

MOMO · ‎10-08-2017

I already made sure that all the serial settings on my emulator are correct - baud, data bits, parity, stop bits, flow control. I tried changing the baud rate using all available baud rates available. But I still have the same problem.

marce1000 · ‎10-08-2017

- Does the problem also persist when you try using the physical console connection ?

M.

-- Each morning when I wake up and look into the mirror I always say ' Why am I so brilliant ? '
When the mirror will then always repond to me with ' The only thing that exceeds your brilliance is your beauty! '

MOMO · ‎10-08-2017

Hi @marce1000,

Im sorry but I'm not sure if I understand what you mean by "physical console connection".

What I have is a rollover cable connected from the serial port of my computer (COM1) to the console port of the c2950. Then, I'm using Putty and TeraTerm for emulator. I'm not sure if this switch is configured.

marce1000 · ‎10-08-2017

- Are you using an official cisco blue console cable ?

First I thought you were accessing the switch over the network; that being said ; can you access the switch through the network and or do you still have the same problem(s) when doing so ?

M.

-- Each morning when I wake up and look into the mirror I always say ' Why am I so brilliant ? '
When the mirror will then always repond to me with ' The only thing that exceeds your brilliance is your beauty! '

MOMO · ‎10-08-2017

Yes, I'm using the blue Cisco rollover (console) cable. I also don't know if the switch is configured. So, this is my only way to access the CLI.

marce1000 · ‎10-08-2017

= If also the boot process can't be observed after a power cycle ; I would advise to execute a hardware reset on the device,

M.

-- Each morning when I wake up and look into the mirror I always say ' Why am I so brilliant ? '
When the mirror will then always repond to me with ' The only thing that exceeds your brilliance is your beauty! '

MOMO · ‎10-10-2017

Catalyst 2950 doesn't have a reset button. To be able to reset this switch you have to "break"the boot process, bypass the startup-config file during the second boot or simply erase the startup-config file.

However, even at ROMMON, characters are still garbled.

marce1000 · ‎10-10-2017

- Try another cable and or another access device (the one putty is running on)

M.

-- Each morning when I wake up and look into the mirror I always say ' Why am I so brilliant ? '
When the mirror will then always repond to me with ' The only thing that exceeds your brilliance is your beauty! '

Bill Longman · ‎10-11-2017

The fact that you are seeing characters in your terminal emulator is evidence that you have a receive line working at a minimum. If the characters are always garbled, that is usually a sign of incorrect word size which means you'll need to fiddle with the number of stop bits, parity and also the word size. However, I would start by debugging the line speed because in my many years of serial comm experience, that's usually the place to start. Even from 300 up to 115200. If none of the speeds work, go back to 9600 and start playing with the word size, parity and stop bits.

Hopefully that will get you somewhere.

MOMO · ‎10-11-2017

Hi Bill,

None of the baud rates (line speed) that I know will work. I started from 110 up to 921600, using Putty and TeraTerm but still with the same result. For the data (word size), I only use 8 since that's the Cisco recommended size. Any values I can use for data size?

And just an added info. I tried connecting this c2950 switch to my Cisco 2600 router, which is working perfectly. All LED activities on both devices are normal. Then, using CDP, I checked if the c2600 can detect the c2950 - and it cannot. So it's either CDP is disabled on this c2950 or there is really something wrong with this and not just about baud.

marce1000 · ‎10-11-2017

- Try another cable and or another access device (the one putty is running on)

M.

-- Each morning when I wake up and look into the mirror I always say ' Why am I so brilliant ? '
When the mirror will then always repond to me with ' The only thing that exceeds your brilliance is your beauty! '

MOMO · ‎10-12-2017

already did. same problem.

Bill Longman · ‎10-12-2017

This is a game we play on our coworkers - set the line to 7-even-1 and see if they can figure it out by the time lunchtime rolls around. Without an oscilloscope, this is just trying different combos. You could try seven bits, or better yet, play with parity and stop bits. You are getting something, so it's a matter of finding what the setting is.

Tell me, when you are booting the node, are you pressing the spacebar a few times so the device can try its autodetection?