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CHECKRAD(5) File Formats Manual CHECKRAD(5)


checkrad -- See if a user is (still) logged in on a certain port.


checkrad [-d] nas-type nas-ip nas-port login session-id


Checkrad is used by the radius server to check if its idea of a user logged in on a certain port/NAS is correct if a double login is detected.

Returns: 0 = no duplicate, 1 = duplicate, >1 = error.


Enable printing of debugging information.

Type of port/NAS. Can be one of:

  • ascend
  • bay
  • cisco
  • cisco_l2tp
  • computone
  • cvx
  • digitro
  • dot1x
  • livingston
  • max40xx
  • mikrotik
  • mikrotik_snmp
  • multitech
  • netserver
  • other
  • pathras
  • patton
  • portslave
  • pr3000
  • pr4000
  • redback
  • tc
  • usrhiper
  • versanet

The "other" type cause checkrad to skip any check and always returns 1.

IP address of the NAS to check.

The NAS port to check (may be ignored by some nas-type).

The login name to check.

Session to check. (actually ignored by all nas-type)




Written by Miquel van Smoorenburg,

This manual page was written by Marco Nenciarini <> for the Debian project (but may be used by others).

13 January 2006