FTP service monitoring

Last published : Sep 22, 2026
To monitor FTP services, the NetScaler appliance opens two connections to the FTP server. It first connects to the control port, which is used to transfer commands between a client and an FTP server. After it receives the expected response, it connects to the data port, which is used to transfer files between a client and an FTP server. Only when the FTP server responds as expected, on both the connections, it is marked UP.
Note: Monitor probes originate from the NSIP address.
The NetScaler appliance has two built-in monitors for FTP services: the FTP monitor and the FTP-EXTENDED monitor. The FTP-EXTENDED monitor is a scriptable monitor. It uses the nsftp.pl script. The FTP-EXTENDED monitor script is enhanced to send secure probes to FTP services. You can create a monitor of type FTP-EXTENDED. The nsftp.pl script is automatically taken from the default directory.
Related information

To send secure FTP probes to FTP services by using the CLI

At the command prompt, type:
add lb monitor <monitorName> <type> -username <string> -password <string> -filename <filename>
Example
add monitor mon1 FTP-EXTENDED -username root -password freebsd -filename fsdf

To send secure FTP probes to FTP services by using the GUI

  1. Navigate to Traffic Management > Load Balancing > Monitors.
  2. Specify the monitor type as FTP-EXTENDED, and set the parameters.
  3. In Special Parameters, specify a File Name, User Name, and Password.
To configure built-in monitors to check the state of FTP services, see Configuring Monitors in a Load Balancing Setup.