In order for BCS to filter your clients' DNS traffic, your outbound IP address must be recognized by the Barracuda Content Shield (BCS) proxy server. If your service provider has not issued you a static IP address, or if you use DHCP, there is a possibility that this IP address could change. If that happens, the BCS DNS proxy server will no longer apply your filtering policies.

To avoid this scenario, you can use the Barracuda Dynamic IP Address Updater Tool to monitor changes to the IP address. This utility can be installed on a workstation or server within your network. If the tool detects a change in the outbound IP address, it will notify the BCS DNS proxy server of the change so that your DNS traffic filtering policies will continue to be applied.

Important notes about the Dynamic IP Updater:

• This tool is only available for Windows.

• This tool needs to be installed on ONE client machine in the network. 

• Optional DNS server override feature: Install the Dynamic IP Updater with an override parameter to only report the location without filtering network traffic on the machine where the tool is installed. See DNS Server Override below.

• To ensure that traffic is being forwarded to the Barracuda DNS instance so that the endpoint location can be updated, set the DNS servers on the Windows machine to the IP addresses indicated on the DNS FILTERING page in the BCS portal.

• When using the Dynamic IP Updater to update a location, the ddns.key files are different for each dynamic location. You can redownload the ddns.key file for an existing location by using the menu next to the location.

To Use the Dynamic IP Address Updater:

If you have defined your network as having a dynamic IP address (see How to Configure DNS Filtering and Policies), you would have been given the option of downloading the Dynamic IP Updater Tool at the end of the setup process. Otherwise, you can get the tool by clicking the More Options (

) in the table row for that entry on the DNS Filtering page.

Download the installer and key files from the Dynamic IP Updater window, and follow the procedure below to complete the installation.

1. Click Download Installer and save the installer on your local machine or network. Click Download Key on the page to get the installer key, which you will use when installing the tool on the endpoint machine. The installer file is named Dynamic IP Updater.msi.The key file is named ddns.key.

2. To ensure that traffic is being forwarded to the Barracuda DNS instance so that the endpoint location can be updated, set the DNS servers on the Windows machine to the IP addresses indicated on the DNS FILTERING page in the BCS portal.  

3. On an endpoint machine, run the Dynamic IP Updater installer.

4. Accept the license agreement, and select either the option to type/paste in your key, or import the key file you downloaded in Step 1.

5. After the installation completes, the Dynamic IP Updater starts automatically. However, if the utility gets terminated, you can restart it in one of two ways:

• Click on the Dynamic IP Updater shortcut in the Windows Start menu.   – OR –

• Simply reboot the client machine

When the Dynamic IP Updater Tool is running, you will see the Windows command line window indicating the currently assigned IP address for the client. Every 5 minutes, the Dynamic IP Updater Tool checks to see if the outbound IP address has changed; if so, it automatically updates the IP address on the BCS DNS proxy server.

When using the Dynamic IP Updater to update a location, the ddns.key files are different for each dynamic location. You can redownload the ddns.key file for an existing location by using the menu next to the location.

DNS Server override

To use the Dynamic IP Updater DNS server override feature:

1. Create a comma separated list of DNS Servers, using the Primary and Secondary server IP addresses from upper right of the Dashboard page. For example: SERVER=34.203.72.42,34.203.170.29
   If this parameter is passed during installation, the Dynamic IP Updater executable will only report the location, and not filter the web traffic for the machine it is running on.

2. From the command line, explicitly pass DNS Servers via the SERVER parameter to the installer. Replace 'my\path\to\' with the valid path to where the ddns.key file is stored:

The Dynamic IP Updater is automatically started after installation and after reboot. The process 'ddns.exe' is invoked with server override:

"C:\Program Files (x86)\Barracuda\Dynamic IP\ddns.exe" "-server=34.203.72.42,34.203.170.29"