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Barracuda SSL VPN

This Product is End-of-Life and End-Of-Support

End-Of-Life and End-Of-Support on December 1st, 2020: All Barracuda SSL VPN sales will cease; neither new sales nor any renewals will be available. If you currently hold a maintenance and support contract, you will continue to receive our award-winning support and services until your contract expires. Please see the End-Of-Life definition as described in the End of Support and End of Life Information.

How to Configure IPsec

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You can configure the Barracuda SSL VPN to allow L2TP/IPsec connections from remote devices using an L2TP/IPsec client that supports using a pre-shared key (PSK) as an authentication protocol. L2TP/IPsec clients are also standard on most smartphones, including Apple iPhones and iPads, smartphones running Android 1.6 or higher and tablets running Android 3.0 or higher.

Before you begin

On your organization's firewall, allow authentication traffic to and from the Barracuda SSL VPN. UDP over ports 500 and 4500 must be enabled to reach the Barracuda SSL VPN for L2TP/IPsec connections to function.

Step 1. Configure the IPsec server

On the Barracuda SSL VPN, configure the IPsec server to allow your remote users to authenticate and connect to the protected network:

  1. Log into the SSL VPN web interface.
  2. Navigate to the RESOURCES > IPsec Server page.
  3. Verify that you have selected the correct user database on the top right of the page.

  4. In the Create IPsec Server section, enter a descriptive name for your IPsec server.
  5. Enter the preshared key. The string must be alphanumeric.
  6. In the IP Range Start/End fields, enter the first and last IP address of the DHCP range that should be assigned to remote systems connecting via IPsec.

    This IP range must reside in the network range that is configured in the TCP/IP Configuration of the applicance interface, and MUST NOT be part of any other DHCP range on your LAN.

  7. From the Policies list, select the available policies that you want to apply to the IPsec server, and add them to the Selected Policies list.

  8. Click Add.

The IPsec Server is now created and appears in the IPsec Server section. You can test the configuration by clicking the Launch link associated with the entry.

Step 2. Create an L2TP/IPsec connection

On your remote device, create an L2TP/IPsec connection to the Barracuda SSL VPN.

If the remote device has had a VPN client uninstalled at some point, then make sure that the IPsec service has been re-enabled in order to allow connections via L2TP/IPsec.

  1. Log into the Barracuda SSL VPN on the client device.
  2. Go to the Resources tab.
  3. From My Resources, select the IPsec server and click to launch it.
    During the connection, you will be prompted with a certificate warning message:
    1. Go to your network connections, right click the SSL VPN connection and go to the properties.
    2. Under the Security tab, click Advanced settings in the Type of VPN section, and enter the preshared key.
    3. Click OK twice to exit the connection properties.
  4. Connect to the IPsec server.

Step 3. Apply the installation to the client device

Once you are successfully connected, provision the device configuration to the client device. Be aware, that, for this procedure, the user must have been granted the appropriate access rights. For more information, see: Provisioning Client Devices.

  1. From the Resources tab of the client device, go to Device Configuration.
  2. Tick the checkbox unter the IPsec server entry.
  3. Click Provision on the bottom of the page.