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Closing telnet loopbacks to async lines

We're using a 2600 with 32 async lines as terminal server for console access to our central network equipment.

Plan is to build a menu on the 2600 such as:

menu console command 1 telnet <2600 ip> <port number>

menu console text 1 Router A console

Works great, except when closing connections.

We can log out from the console port on the equipment in question, but the 2600 doesn't drop the telnet connection to itself.

We have to do "Ctrl-Shift-6 x" to get back to the menu, and the session still hangs.

Any way I can close those telnet sessions automatically?


Re: Closing telnet loopbacks to async lines

You have to kill the telnet session manually unless you want it to timeout after a few minutes of inactivity. Loggin out fron console does not mean that it will disconnect itself. You might want to look at the following commands:

Service tcp keepalive in

Service tcp keepalive out

I think the default timeout is like 5 minutes.

New Member

Re: Closing telnet loopbacks to async lines

service tcp-keepalives-in and service tcp-keepalives-out merely tells IOS to send TCP keepalives on TCP sessions to/from the box, but it doesn't help detect idle sessions.

New Member

Re: Closing telnet loopbacks to async lines

Do you just need to type "disconnect" after you press the telnet suspend escape sequence ctrl-shift-6?

----------------------------------------CCO Text--------------------------------------------------


The reverse Telnet session must be terminated before the line can accept incoming calls. If you do not terminate the session, it will be indicated in the output of the show users command when it returns a modem state of ready if the line is still in use. If the line is no longer in use, the output of the show line value command will return a state of idle.

Terminating the Telnet session requires first suspending it, then disconnecting it. To suspend a Telnet session, enter the escape sequence Ctrl-Shift-6 x (press Control-Shift-6, let go, then press x). Enter the disconnect EXEC command to terminate the Telnet session.



Re: Closing telnet loopbacks to async lines

This capability will finally be added with CSCdz21644. This will be added to 12.2T.

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