Application Delivery Management

How to add RADIUS authentication servers

A RADIUS authentication server operates by using the User Datagram Protocol (UDP). The RADIUS server receives a user’s connection request, authenticates the user. The server then returns the configuration information to the system that delivers services to the user. The RADIUS server is connected to a network access server (NAS). When the NAS sends an Access-Request, the RADIUS server searches its database for the user name and other details. If the user name does not exist in the database, the RADIUS server immediately sends an Access-Reject message, or it can load a default profile on Citrix ADM. In RADIUS, authentication and authorization are coupled together. If the user details are authenticated, the RADIUS server returns an Access-Accept response. It also sends a list of attribute-value pairs that describe the parameters to be used for that particular session.

Configuring a RADIUS authentication server

  1. In Citrix ADM, navigate to System > Authentication > RADIUS.

  2. On the RADIUS page, click Add.

  3. On the Create RADIUS Server page, set the parameters, and click Create to add the server to the list of RADIUS authentication servers.

  4. The following parameters are mandatory to create the RADIUS server:

    • Name – type the name of the RADIUS server

    • Server Name / IP Address – type the Server name or the IP address of the RADIUS server

    • Port – by default, port 1812 is used for RADIUS authentication messages. You can specify a different port number, if necessary.

    • Time-out (seconds) – type the number of seconds. The time that the Citrix ADM system waits for a response from the RADIUS server.

    • Secret Key – type any alphanumeric expression. The key that is shared between the Citrix ADM and the RADIUS server for communication.

  5. Click Details to expand the section and set the additional parameters.

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You can provide more optional details while adding a RADIUS server. Some of the additional parameters you can enter are NAS details, vendor information, attribute information, and type of password authentication.


For RADIUS authentication to work, ensure that the group configured on Citrix ADM and the group extracted through the RADIUS user is the same. The user is authorized based on the permissions assigned to the group.

For example, consider a scenario in FreeRADIUS server, where,

  • Cleartext-Password = “1.citrix”

  • Group-Names = “radiusgroup1, group1”

In this case, the user belongs to two groups - radiusgroup1 and group1. The group separator in this case is “,”

If you are logging on Citrix ADM as a RADIUS user “RadiusUser1” who belongs to group “radiusgroup1,” ensure that the same group name “radiusgroup1” is configured on Citrix ADM as well.

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Provide the details regarding the vendor ID, attribute type, group separator (if applicable) for the group extraction to happen as shown in the following image.

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How to add RADIUS authentication servers