EXFO FTB-2 - Manual (Page 428)

Communicating Through TCP/IP over Telnet
418 FTB-2 and FTB-2 Pro
Internal Commands of the TCP/IP over Telnet Protocol
CLOSE LINS
Syntax: CLOSE LINS<Unit_Number><Module_Slot_Number>
You must specify the unit number and the slot number identifying the
module for which you want to close the connections.
This command allows to close active connections. You can send this
command to close all client’s connections with any module, including the
current connection.
If the command is not executed successfully, the possible reasons could
be:

The module is not present at the specified position.

The provided information does not correspond to a valid LINS.