# Restricting access by Parallels Client type and build number

You can specify a minimum requirement for the Parallels Client type and version number in order for it to connect to the Parallels RAS Farm or to list published resources. In addition, you can set the Parallels Client security patch level (described later in this section).

To specify Parallels Client requirements:

1. In the RAS Console, select the **Connection** category and click the **Allowed Devices** tab.
2. The **Allow only clients with latest security patches** option specifies the Parallels Client security patch level. If the option is selected, only clients with latest security patches applied will be allowed to connect to Parallels RAS. This option must normally be selected to protect your environment from vulnerabilities. You should only clear it if you must use an older version of Parallels Client with no security patches installed. For more information, please see the following KB article: <https://kb.parallels.com/en/125112>.
3. In the **Mode** drop-down list, select from the following options:
   * **Allow all clients to connect to the system**. No restrictions. All Parallels Client types and versions are allowed full access.
   * **Allow only the selected clients to connect to the system**. Allows you to specify Parallels Client types and versions that are allowed to connect to the Parallels RAS Farm. Select the desired Parallels Client types in the **Clients** list. To set the **Minimum build** value, right-click the client type and choose **Edit**. Type the version number directly in the **Minimum build** column.
   * **Allow only the selected clients to list the published items**. Allows you to specify Parallels Client types and versions that can list published resources. Compared to the option above, this one does not restrict Parallels Clients connecting to Parallels RAS. Select this option and then select the desired Parallels Client types in the **Clients** list. To set the **Minimum build** value, right-click the client type and then click **Edit** in the context menu. Type the version number directly in the **Minimum build** column.

If a restriction is configured and a Parallels Client is excluded from the list, the user running it will receive a corresponding error message and will be advised to contact the system administrator.


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