not able to access switch via console

[mkhawaja99]

Hello .....

I have 2960 switch and i can't access it using my console cable .

I can access other switches in my network ( 3560 & 2960 ) but i can't access only this switch.

may be the console port in the switch damaged? or it's a bug ?? !!! although the switch is worked normally.

[cadet alain]

Hi,

if you can access via ssh/telnet can you post sh ver  output.

Also can you try with different speed settings on your terminal software.

Regards.

Alain

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[mkhawaja99]

Hello Alain ,

- Unfortunately this switch not have an IP address to access it via ssh/telnet.

- I try with different speeds ( 2400 ) but still can not view anything in putty ( black screen only ) .

thanks.

[shah.agam]

Hi

I am new to this networking and trying to start a home LAB for CCNA. I am having the same issue with Catalyst 3550 and 3524XL.

Just a blank screen. Saw that no post after 3 years and safe to assume that you may have the solution for the same. Can spread some light on this issue so i can try same with my home lab!

Thanks in advance!

[tsmullins]

We had a similar issue once,

It was an authentication issue.

Shane

[Rahul Kukreja]

Check what is configured under line con 0 (if there is any old configuration available) -

line con 0

no exec ----------> If this configured then you cannot access the switch via console.

If possible try to reset to factory default.

Regards,

Rahul

[mkhawaja99]

Really i don't know the configuration of this switch because i can't access to it .

when i connect console cable to the switch, start putty program and chose the com port ; all i have is black screen !!

i don't know where is the problem : in the console port of the switch or may be a bug ??

regards

mohammad.

[Rahul Kukreja]

Mohammad - Honestly at this point it is hard to comment whether it is a software issue or hardware.

I would try to reload and then reset if it doesn't work.

Regards,

Rahul

[graham smart]

I would have to agree with Rahul,

A reload is probably your best bet.

I would do the following beforehand..
1) Figure out what Vlans ( if any ) you have, and what ports they need to be on.

2) Figure out any possible special config for ports beforehand.

3) Get a spare switch ready.

4) Reload and hope it comes back to life.

If it doesnt come back to life then at least you have a spare and some idea of what the config may need to be to get it up and running with minimal configuration.

I would suggest however that next time you get on it, Take a copy of its config

Good luck. It may just be that the console output has hung ( Ive had it happen before )

-Graham
Please note: My comments are simply suggestions. I cannot be held liable for any loss of data, life or marbles due to following my instructions.

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[mkhawaja99]

Thanks Graham;

i will summary what i do:

- change the speed sitting to 2400, but the console connection still not working.

- reload the Switch by unplug the power cable then plug it , the switch running and operate normally as it was without the problem solved.

- I cannot reset the switch because the CLI not view anything to do the reset operation.

The configuration in the switch is simple and there is one VLan only . i think to change the switch

. It may just be that the console output has hung ( Ive had it happen before ) 

Hung??!! , what did you do when this happen??

Finally ; can i configure the switch using ethernet port ???

Regards.

[cadet alain]

Hi,

Why didn't you try multiple speed instead of only one?

if you have a VLAN interface up and running and you know in which subnet it is then if you've got login on the vty and an

enable secret password configured, you'll be able to get into privileged mode and maybe solve the problem.

Regards.

Alain

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[mkhawaja99]

Thanks Alain,

• No interface vlans are configured on the switch , so i cannot access it via ssh/telnet.
• I change the speed sitting but the problem still occurred.

Regards.

Mohammad

[graham smart]

Mohammad Al-Khawaja wrote:
Thanks Graham;
i will summary what i do: 
- change the speed sitting to 2400, but the console connection still not working.
- reload the Switch by unplug the power cable then plug it , the switch running and operate normally as it was without the problem solved.
- I cannot reset the switch because the CLI not view anything to do the reset operation.
The configuration in the switch is simple and there is one VLan only . i think to change the switch 
. It may just be that the console output has hung ( Ive had it happen before ) 
Hung??!! , what did you do when this happen??
Finally ; can i configure the switch using ethernet port ???
Regards.

I just reloaded the offending switch..

Erm.. You say you ahve the console on 2400 ? Shouldnt it be 9600 baud rate?

BPS: 9600

Databits: 8

Parity: None

Stop bits: 1

Flow control: None

You CAN configure using an ethernet port however you first need to enable it all via the console port So you are stuck there.

To access via ethernet you need to give vlan1 an  ip address ( for example 192.168.0.1 255.255.255.252 )

Then enable telnet on the VTY and set a password.

Then plug a pc into a port that is vlan 1 ( switchport mode access , switchport access vlan 1 )

Then give your PC an ip address of 192.168.0.2 255.255.255.252

Telnet 192.168.0.1

-Graham
Please note: My comments are simply suggestions. I cannot be held liable for any loss of data, life or marbles due to following my instructions.

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[David Torr]

Had the same issue on 2960's that have been working for years untill we upgraded the IOS. Turned out that the new IOS was using more memory than the older version, the switch would priorities switching so everything else was still working fine, just didn't have enough memory available to enable telnet/console access.

Had to reboot the switch, console in and reduce the size of Logging to get past this issue.

[mostafasaeed]

Hi,

Actually it happen with me, iam still have the problem in the console, but i get the point and i put the basic configuration  of vty.

i tried to unplug the power cable and plug it again while the console is connected, it seems that it`s work fine, but i hanging again after it` boot. so i realize that the console get the output while something changed, i try to connect one pc to a port and disconnect it again, it works, in normal case it will show in console that port has been down and up, this was happen to me it appears the console message and appear also any command it write it.

so any command i write it i make the same exercise, connect and disconnect the pc. till i make the basic configuration which give me ability to login telnet.

Regards,