Clearing LSN Sessions

Last published : Sep 30, 2026
You can remove any unwanted or inefficient LSN sessions from the NetScaler appliance. The appliance immediately releases resources (such as NAT IP address, port, and memory) allocated for these sessions, making the resources available for new sessions. The appliance also drops all the subsequent packets related to these removed sessions. You can remove all or selected LSN sessions from the NetScaler appliance.
Related information
Large Scale NAT

To clear all LSN sessions by using the command line interface

At the command prompt, type:
flush lsn session

show lsn session

To clear selective LSN sessions by using the command line interface

At the command prompt, type:
flush lsn session [-clientname <string>] [-network <ip_addr> [-netmask <netmask>] [-td <positive_integer>]] [-natIP <ip_addr> [-natPort <port>]]

show lsn session

Example

Clear all LSN sessions existing on a NetScaler
flush lsn session

Done
Clear all LSN sessions related to LSN client entity LSN-CLIENT-1
flush lsn session -clientname LSN-CLIENT-1

Done
Clear all LSN sessions related to a subscriber network (192.0.2.0) of LSN client entity LSN-CLIENT-2 belonging to traffic domain 100
flush lsn session -clientname LSN-CLIENT-2 –network 192.0.2.0 –netmask 255.255.255.0 –td 100

Done

To clear all LSN sessions by using the configuration utility

Navigate to System > Large Scale NAT > Sessions, and click Flush Sessions.

Parameter Descriptions (of commands listed in the CLI procedure)

  • flush lsn session
    • clientname
      Name of the LSN Client entity. Maximum Length: 127
    • network
      IP address or network address of subscriber(s).
    • netmask
      Subnet mask for the IP address specified by the network parameter.
      Default value: 255.255.255.255
    • td
      Traffic domain ID of the LSN client entity.
      Default value: 0
      Minimum value: 0
      Maximum value: 4094
    • natIP
      Mapped NAT IP address used in LSN sessions.
    • natPort
      Mapped NAT port used in the LSN sessions.