Blank screen on ssh connection

[aadil_nabee]

Hi Guys,

Please can someone help...

If i try to ssh to a 3750 switch on our 4th floor, it ask's me for a username and password.

After entering the password, it doesnt connect. It shows a blank screen with a flashing cursor.

If i connect to the switch directly via console port, i can see port uplink and downlinks but still cant do anything more.

AN.

[Peter Paluch · Accepted solution]

Hello Aadil,

Can you afford reloading the switch? This looks like a bug that has been discussed here a couple of times - some IOSes like to consume inordinate amounts of memory and causing high CPU load to the point of being unable to access the CLI. Also, have there been any changes in the configuration of con0 and vty lines?

Best regards,

Peter

[aadil_nabee]

Thanx Peter,

Yes there was some changes made, was trying to set WOL.

I manage to set it up on our floor switch but the moment i tried to do i on the 4th floor it kicked me out and i lost the connection. I then restarted the switch, thats when i cant access the CLI.

I rebooted the switch this morning and all seems fine.

How difficult is it to reload a switch (sorry new to networking)?

Just a question , on the 4th floor i have 5 x 3750 switch. Let say master is switch number 3 and i cant access the CLI.

Is it possible to make master maybe switch number 1, thus being different switch will allow me access to CLI.

[Peter Paluch]

Hi Aadil,

How difficult is it to reload a switch (sorry new to networking)?

Reloading is the same as rebooting, and you wrote that you have rebooted it. Does it work now?

Just a question , on the 4th floor i have 5 x 3750 switch. Let say master is switch number 3 and i cant access the CLI. Is it possible to make master maybe switch number 1, thus being different switch will allow me access to CLI.

I do not have hands-on experience with switch stacks. However, according to what I have found in the documentation, this would not be a good idea, as changing the stack master will result in changing the MAC address of the entire stack. That will in turn cause transient outages, STP recalculations, etc. Moreover, I do not think that you can actually configure a non-master switch, or use it to claim stack mastership - but perhaps someone else will fill me in here.

Best regards,

Peter

[aadil_nabee]

Yes you were right reloading the switch has fixed the problem.

Know what you saying but lets say for example the master is still switch 3 , power drop to the cabinet.

All switch go off , when power is back all switch's start up not in order of master first.

Everything still works and this happened to us a few times, so whichever switch starts up first that will be the master.

Thus the question swapping masters...