---
name: "checkrad"
section: "5"
platform: "linux"
package: "freeradius"
version: "3.2.10-4"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/checkrad"
---

# checkrad(5)

## NAME

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

## SYNOPSIS

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

## DESCRIPTION

**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.

## OPTIONS

- \-d

  Enable printing of debugging information.

- nas-type

  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.

- nas-ip

  IP address of the NAS to check.

- nas-port

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

- login

  The login name to check.

- session-id

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

## SEE ALSO

[radiusd(8)](/radiusd/8.md)

## AUTHOR

Written by Miquel van Smoorenburg, miquels@cistron.nl.

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