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New Member

VTY Randomly Disconnects


I'm having a problem with a 3550 that is randomly kicking me off of a ssh/telnet session with the switch. Sometimes it disconnects in the midst of typing, and other times it disconnect after being idle for a minute or two. It is not due to a network disconnection of any sort. Any ideas??



Re: VTY Randomly Disconnects


can u revert whats the disconnection timeout you have set under your line vty ...

can you copy and paste the config lines under the line vty ..


New Member

Re: VTY Randomly Disconnects


Here's what the config looks like...


line vty 0 4

password 7 08335B5A081D081AC4

transport input ssh


Here's an output of a "sh line vty 0"


Line 1, Location: "", Type: "vt100"

Length: 31 lines, Width: 80 columns

Baud rate (TX/RX) is 9600/9600

Status: Ready, Active, No Exit Banner, Autoconfig Running

Capabilities: none

Modem state: Ready

Special Chars: Escape Hold Stop Start Disconnect Activation

^^x none - - none

Timeouts: Idle EXEC Idle Session Modem Answer Session Dispatch

00:10:00 never none not set

Idle Session Disconnect Warning


Login-sequence User Response


Autoselect Initial Wait

not set

Modem type is unknown.

Session limit is not set.

Time since activation: 00:01:32

Editing is enabled.

History is enabled, history size is 10.

DNS resolution in show commands is enabled

Full user help is disabled

Allowed input transports are ssh.

Allowed output transports are telnet ssh.

Preferred transport is telnet.

No output characters are padded

No special data dispatching characters


Thanks for your help!!

Re: VTY Randomly Disconnects


can you check out the ssh time out configured over there in your router.

This is the command to setup the timeout for SSH.

ip ssh time-out 60

in my earlier post i was visualizing normal ordinary telnet not SSH..

also refer this link for more info about ssh and the troubleshooting guide..


New Member

Re: VTY Randomly Disconnects

Thanks you.

I have modified the ssh time-out, but this does not resolve the issue. The issue is even present when I use telnet.

The disconnect does not occur over a regular amount of time. I sometimes get disconnected in 5 minutes, and some time after 5 seconds. It's kind of irritating. :)


New Member

Re: VTY Randomly Disconnects

Hello Everyone,

I'm having the same problem, so far with 1700 routers. When configuring them from telnet it kicks me out and I lose all connectivity to it. Router has to be reloaded =S. There aren't any bugs associated to IOS. One router was even replace and it still happens the same. Does anyone know what could be going on? it's driving me nuts!!!!

Thank you all,


New Member

Re: VTY Randomly Disconnects


I had the same problem.

After hours of reserch I dicovered that on my net the Cisco switch had on the administrative interface the same ip address with the address of a host on the net.

So I reserved the address of the switch in the dhcp pool and I put the host to retake its address.

Now everything works well.

Hope that help!

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