# Secure Gateway security

You can allow or deny user access to a Secure Gateway based on a MAC address. This can be accomplished using the **Security** tab in the **RAS Secure Gateway Properties** dialog.

## **Using Site defaults**

To use Site default settings, click the **Inherit default settings** option. To specify your own settings, clear the option. For more info, see [**Site defaults (Gateways)**](/landing/ras-admin-guide/v20-en-us/parallels-ras-20-administrators-guide/ras-secure-gateway/configuring-a-ras-secure-gateway/site-defaults-secure-gateways.md).

## **Configuring security**

To configure a list of allowed or denied MAC addresses, click the **Security** tab and select one of the following options:

* **Allow all except.** All devices on the network will be allowed to connect to the Secure Gateway except those included in this list. Click **Tasks** > **Add** to select a device or to specify a MAC address.
* **Allow only**. Only the devices with the MAC addresses included in the list are allowed to connect to the Secure Gateway. Click **Tasks** > **Add** to select a device or to specify a MAC address.

Please note that the Secure Gateway MAC address filtering is based on ARP, so client and server must be on the same network for the filtering to work. It does not work across network boundaries.


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