Cabletron Systems CSX1000, CSX1200 Emergency Telnet Server Port Number Background Information

USER’S GUIDE

EMERGENCY TELNET SERVER PORT NUMBER BACKGROUND INFORMATION

There are some Telnet client programs that do not clear Telnet connections when terminating Telnet sessions. Since they do not clear the Telnet connections, those connections stay alive and soon all Telnet sessions are used up. Once this happens, no more Telnet sessions can be established until the inactivity timer of one of the sessions expires.

However, if the idle timer of the administrative session is disabled, you may need to reboot the CyberSWITCH. To avoid this, a special Telnet server that uses a particular TCP port is provided. If you Telnet into this special server (the Emergency Telnet Server) you will be placed into a session which prompts you for an action on each of the existing Telnet sessions.

The emergency Telnet session allows you to terminate Telnet sessions only when all Telnet sessions are used up. An emergency Telnet server is available to clean up dead Telnet sessions. This Telnet server needs a unique port number in order to function.

The following example screen illustrates a successful emergency Telnet session:

Emergency	Telnet session		active
Enter password(s)		for ’ADMIN’ user.
Enter password: ******
Login-Id	Sess-Id	Date/Time		Idle (sec)	Command Type (From)
--------	-------	------------		----------	--------	------------------------
ADMIN	257	May 20	12:34	800	MANAGE	Telnet (199.120.211.70)
Do you wish to terminate			this session (Y or N) [default = Y]? <RET>
Login-Id	Sess-Id	Date/Time		Idle (sec)	Command Type (From)
--------	-------	------------		----------	--------	---------------
ADMIN	511	May 20	12:30	1025	SHELL	199.120.211.71
Do you wish to terminate			this session (Y or N) [default = Y]? <RET>
Login-Id	Sess-Id	Date/Time		Idle (sec)	Command Type (From)
--------	-------	------------		----------	--------	---------------
ADMIN	734	May 20	12:35	740	LOGIN	199.120.211.69
Do you wish to terminate			this session (Y or N) [default = Y]? <RET>

The following screen illustrates a situation where Telnet sessions are still available. The Emergency Telnet session then simply informs you that you can not terminate Telnet sessions under these circumstances (no emergency exists).

Emergency Telnet session active

Enter password(s) for ’ADMIN’ user.

Enter password: ******

There are Telnet connections available for administrative sessions.

Please use an administrative session to terminate abandoned sessions.

154 CyberSWITCH