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Barracuda CloudGen Firewall

Attention

Barracuda CloudGen Firewall version 8.0 is a cloud-only version. It is currently not available for on-premises deployments and can only be deployed in Microsoft Azure, Amazon Web Services, or Google Cloud Platform public clouds.

How to Configure a Transparent Redirect

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To transparently forward connections to a Barracuda Web Security Gateway located in a DMZ behind a CloudGen Firewall, configure the Dst NAT access rule to not rewrite the source and destination addresses of the connection. Using the original source and destination IP addresses allows the Barracuda Web Security Gateway to apply filtering policies and create meaningful statistics as if it were directly connected to the client.

The Web Security Gateway described here can be replaced by any appliance processing traffic that requires the original source and destination IP addresses to remain unmodified.

transparent_redirect_rules.png

Before You Begin

  • Verify that the Forwarding Firewall service is using Feature Level 7.2 or higher.
  • The CloudGen Firewall and the proxy must be directly connected to the same subnet (within the same ARP domain).
  • (optional) Enable SSL Inspection in the firewall. For more information, see SSL Inspection in the Firewall.
  • The Web Security Gateway must be running firmware version 10.0.0 or higher and use Transparent SSL Inspection.

Step 1. Create a Transparent Redirect Dst NAT Access Rule

Create the Dst NAT access rule to forward all traffic to the proxy.

  1. Go to CONFIGURATION > Configuration Tree > Box > Virtual Servers > your virtual servers > Firewall > Forwarding Rules.
  2. Click Lock.
  3. Create an access rule to forward selected traffic coming from your clients:
    • Action – Select Dst NAT.
    • Source – Select Trusted Networks. Or, you can enter the network the client using the Web Security Gateway is in.
    • Destination – Select Internet.

    • Service – Select HTTP+S.

    • Target List – Enter the IP address without a port. You can use multiple proxies. E.g.. 172.16.0.10

      Do not use network objects containing hostnames (DNS objects). The firewall does not redirect traffic to a hostname or FQDN. 

    • Fallback/Cycle – If you have defined multiple target IP addresses, select how the firewall distributes the traffic between the IP addresses.
      • Fallback – The connection is redirected to the first available IP address in the list.
      • Cycle – New incoming TCP connections are distributed evenly over the available IP addresses in the list on a per-source IP address basis. The same redirection target is used for all subsequent connections of the source IP address. UDP connections are redirected to the first IP address and not cycled.
    • List of Critical Ports – Enter a space-delimited list of ports used.

    • Connection Method – Select Original Source IP.

    • (optional) Application Policy – Enable Application Control and SSL Inspection to gain deeper insight on the traffic redirected to the Web Security Gateway.
    transparent_redirect_00.png
  4. In the left menu, click Advanced.
  5. In the Miscellaneous section, set Transparent Redirect to Enable

    transparent_redirect_01.png
  6. Click OK.
  7. Drag and drop the access rule so that it is the first rule that matches the traffic that you want it to forward. Ensure that the rule is located above the BLOCKALL rule; rules located below the BLOCKALL rule are never executed.

    Make sure to place the rule above all other HTTP/HTTPS rules that match this source and destination.

  8. Click Send Changes and Activate.

Step 2. Create a Pass Access Rule for the Proxy to Access the Internet

  1. Go to CONFIGURATION > Configuration Tree > Box > Virtual Servers > your virtual servers > Firewall > Forwarding Rules.
  2. Click Lock.
  3. Create a PASS rule to allow the HTTP proxy to access the Internet:
    • Action – Select Pass
    • Source – Enter the IP address of the HTTP Proxy.
    • Destination – Select Internet.
    • Service – Select HTTP+S.

    • Connection Method – Select Dynamic NAT.
    • (optional) Application Policy – Select Application Control policies.

    transparent_redirect_02.png

  4. In the left menu, click Advanced.
  5. In the Dynamic Interface Handling section, set Source Interface to Any.
  6. Click OK.
  7. Click Send Changes and Activate.

Step 3. Create a Pass Access Rule for the HTTP Proxy to Access the Client Network

To allow the HTTP proxy to access the client, you must create a PASS rule:

  • Action – Select Pass
  • Source – Enter the IP address of the Web Security Gateway .
  • Destination – Select Trusted Networks
  • Service – Select HTTP+S.

  • Connection Method – Select Original Source IP.
  • (optional) Application Policy – Select Application Control policies.

transparent_redirect_03.png

Step 4. Configure the Web Security Gateway

In order to successfully send the connection from the proxy to the Internet, you must configure the device:

  • Route to the Internet using the firewall as the gateway.
  • Route to the internal client network using the firewall as the gateway.
  • Traffic must use the IP address of the Web Security Gateway as the source IP address for outgoing connections.
  • The Web Security Gateway must accept the HTTP and HTTPS connections on the same port as the firewall.

For more information, see How to Configure a Transparent Redirection from a Barracuda CloudGen Firewall.

Step 5. Import the Web Security Gateway's Root Certificate

If you are running SSL Inspection on the Cloud Firewall, you must add the root certificate used for SSL Inspection on the Web Security Gateway to the Trusted Root Certificates

Download the Root Certificate on the Web Security Gateway

On the Web Security Gateway, go to ADVANCED > SSL Inspection and Download  the Root Certificate for Browsers. You now have the webfilter.barracuda.pem file containing the root certificate on the client running Barracuda Firewall Admin.

wsg_download_root_cert.png

  1. Go to CONFIGURATION > Configuration Tree > Box > Virtual Servers > your virtual servers > Firewall > Security Policy Settings.
  2. Click Lock.
  3. Click + in the Trusted Root Certificates list and select Import from PEM File.  A file dialog opens.
    import_root_cert_01.png
  4. Select the file containing the root certificate you previously exported from the Web Security Gateway.
  5. Enter a Name.
  6. Click OK
  7. Click Send Changes and Activate.

The certificate is now listed in the Trusted Root Certificates list.

import_root_cert_02.png

Next Steps

Import the root certificates from the CloudGen Firewall and the Web Security Gateway on the clients to avoid SSL certificate errors.

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