Unable to login to Cisco 2960 via console through Terminal Server

[kishore.rajani]

Hi,

I have a set-up with multiple C2960 and C3750 switches. All these devices are being managed remotely.

So basically I login to C2901, which is used as a Terminal Server,  and reverse SSH to the console of each device.

That's - I have assigned an IP to each port of the terminal server so that I can SSH directly to the desired device through via the mapped IP.

Now, recently I had to restart couple of switches - one C2960 and C3750. I initiated the reboot via console connection remotely. I could see the device logs for some time and then the logs stopped and there was no reaction from the console irrespective of any command I tried to enter.

I tried resetting the line on the terminal server, but that didnt help.

Now when I try to SSH the IP mapped to console of that particular device - i dont get any login prompt and there is no effect on device after giving any command. Although i can see the logs on the console session - but cant do anything.

I have a second way of connecting the device via inband- management, and checked the device config found it correct. It is same as other devices which are working correctly.

Both C3750 and C2960 are behaving exactly same - can see logs on console but see effect of even pressing enter - not getting login prompt as well.

Any help in getting this resolved would be highly apreciated.

Regards,

Kishore

[Stuart Gall]

Could be CR LF mapping on the port.
or console logins disabled

Sent from Cisco Technical Support iPad App

[kishore.rajani]

HI Stuart,

I can access other devices through the terminal server, just these two are problematic.

the config is exactly same on other workign devices..

when i rebooted these devices via console (Terminal server), thats when the problem started.

Regards,

Kishore

[Stuart Gall]

Hi Kishore,

I understand that. You are seeing log messages so RS232 is working one way.

You can not send though.

Posibilities are

     some issue with flow control.

     Some sort of hardware issue.

What I was saying is that I have had an issue where I was sending data but the router wanted CR/LF and my session was sending CR so I never saw any response. Just something worth looking at

I would try swapping the console ports between a working device and one of the problem devices. Then at least you will know which side the problem is.

[kishore.rajani]

Sorry for coming back so late on this. The issue remains unresolved. What I have done is that I moved the HWIC Card to other port and can reach the devices. SO it looks more of a hardware issue than the config related.

[vicente78]

Hello Rajan, did you still remember this issue? If so, please let me know if you solved it.

Thank you.

heleno 

[vicente78]

I'm having the same issue with my 3750 switches. I have 4 3750 SW, (three 48 ports, and one 24p metro) Only 24p one is working via Access server config,using octal cable.  I can reverse telnet to the 24p one, but none of 48 ports  switches is working. So my issues are:

Prob 1 - 3750 48 console port will work on the octal cable via my console port. I have tested all  (1-8) cable on  my router 1, that is working fine via ACCEss server, and they are work (I see LED light when connected). But i see no LED light when connected to octal to my 48p switches. When i connect with my serial to usb cable the 48p switches console works fine, but not with octal cable, through my console server - no LED, Error when trying to connect - "destination unreachable".

**Prob 2 - One of my 1841 router the console port stopped worked. I can see it logs when reboot it, but then it just stuck, and no response on the console cable. connecting to Octal cable no response at all.  

**I spent hour and hours t-shooting my router console port, after clearing tty line, changing BAUD rate speed, resetting router few times, with no result. I finally got my router console port to work. bu resetting the confreg. Here is what i did: I logged into "rommon", and changed the confreg to 0x2142 > reset the router  > the console port worked  > then I check my config saved it > changing back the confreg to 0x2012  > the reset the router again. The console port on the picture is working fine.

The prob 1 still not resolved. If you have any idea how to fix that, please share. 

Appreciate your time.

Heleno