Scale set private VNet protection with Azure Firewall deployment

This option describes how to deploy a scale set of virtual appliances behind the Azure Firewall to provide advanced network protection. Deploying a scale set behind the Azure Load Balancer provides additional layers of availability which translates to minimal disruption if a virtual appliance experiences an outage.

IMPORTANT: Internet connectivity notice

During the Deploy the Network Security virtual appliance step, the Network Security virtual appliance is configured behind a standard internal load balancer. The placement of this load balancer blocks the outbound internet connectivity by default unless internet connectivity has been explicitly declared. For this deployment, there are two configuration options that allow outbound connectivity so that your Network Security virtual appliance can communicate with Cloud One Network Security.

Option 1: Add a NAT gateway to the management subnet to allow outbound connectivity. This option is configured before the Network Security virtual appliance is deployed.

Option 2: Add a public load balancer with an outbound rule that allows outbound connectivity. This option is configured after the Network Security virtual appliance is deployed.


Complete these tasks to set up your environment:

  1. Create a resource group
  2. Create spoke virtual network and subnets
  3. Create hub virtual network and subnets
  4. Add peering to connect the hub and spoke-VNets
  5. Add a NAT gateway to the management subnet
  6. Deploy the Network Security virtual appliance
  7. Create an outbound-only public load balancer (optional)
  8. Configure the firewall
  9. Configure route tables


Before you begin


Create a resource group

Create a resource group if one does not already exist in your environment.

  1. Navigate to Resource groups+ Add.
  2. Select your subscription, name the resource group, then select a region.
  3. Click Review + Create.


Create the spoke virtual network and workload subnet

  1. Navigate to Virtual Networks+ Add.
  2. Enter values for the fields in the Basics tab, naming the instance Spoke-VNet.
  3. In the IP Address tab, edit the IPv4 address space and enter a new address.
  4. Click + Add Subnet and enter these details:
    • Subnet name: Workload1-Subnet
    • Subnet CIDR (example): 10.1.1.x/x
  5. Click OK.
  6. Skip the Security and Tags tabs.
  7. Click Review + Create, and then click Create.


Create a Workload virtual machine (optional)

Follow these steps if you are creating this environment as a proof of concept or if you do not have an existing workload in your environment.

  1. Navigate to Virtual machines+ AddVirtual machine.
  2. In the Basics tab, fill in the required fields. Enter the following for the Name and Inbound port rules:
    • Name: WorkloadVM
    • Public inbound ports: None
  3. In the Disks tab, select Standard HDD for the OS disk type and configure the other settings.
  4. In the Networking tab, enter these values:
    • Virtual network: <Your Spoke-VNet>
    • Subnet: WorkloadSubnet
    • Public inbound ports: None
  5. Fill in the information in the remaining tabs.
  6. Click Review + Create, and then click Create.
  7. Write down the Private IP address after the deployment is complete.


Backend workloads example

If you followed the steps above to create a workload in your Azure environment, the following table provides an example of configuration details for two virtual machine web workloads. Install an HTTP server if you intend to configure backend workloads after they are created.

Network interface Subnet IP example
WorkloadVM1 WorkloadSubnet1 10.3.x.x
WorkloadVM2 WorkloadSubnet2 10.4.x.x


Create the hub inspection virtual network and subnets

Use the procedure below to manually set up the inspection-VNet (hub) and subnets. You will select all of the subnets when you deploy your Network Security virtual appliance.

  1. Navigate to Virtual Networks+ Add.

  2. Enter values for the fields in the Basics tab, naming the instance Hub-VNet.

  3. In the IP Address tab, edit the IPv4 address space and enter a CIDR.

  4. Click + Add Subnet and enter the following information to create four subnets:

    Subnet name Subnet CIDR examples
    Management-subnet 10.0.0.x/x
    Inspection-subnet 10.0.1.x/x
    Sanitized-subnet 10.0.2.x/x
    Loadbalancer-subnet 10.0.3.x/x

    NOTE

    The internal load balancer (ILB) is created when you deploy your Network Security virtual appliance from Azure Marketplace.



  5. Skip this step if you already have an Azure Firewall or a third party firewall set up.
    In the Security tab, select Enable for the Firewall setting and fill in the firewall details.

    • Firewall name: AzureFirewall
    • Firewall subnet CIDR (example): 10.0.100.x/x
    • Public IP address: Click Create New → add an IP address, select Regional or Global, then click OK.
  6. Click Review + Create, and then click Create.


Add peering to connect the hub and spoke VNets

  1. Navigate to the Virtual networks page.
  2. Click Spoke-VNetPeerings+ Add.
  3. The peering connection is from the Spoke-VNet to the inspection VNet. Enter the following configuration details, then click Ok.
    • Peering connection name: Spoke-to-Hub
    • Virtual network deployment model: Resource manager
    • Subscription: Your subscription
    • Virtual network: <your Spoke VNet>
    • Peering connection name: Hub-to-Spoke
    • Allow virtual network access from Hub-VNet to Spoke-VNet: Enabled
    • Allow virtual network access from Spoke-VNet to Hub_VNet: Enabled
    • Allow forwarded traffic from Spoke-to-Hub: Enabled
    • Allow virtual network access from Hub-to-Spoke: Enabled
    • Allow gateway transit: Disable


Add a NAT gateway to the management subnet

If you chose option 1 in the Internet connectivity notice section, add a NAT gateway associated with the management subnet to your configuration to allow the Network Security virtual appliance to communicate with Cloud One – Network Security.


NOTE

There is an option to automatically generate a NAT gateway when you deploy the Network Security virtual appliance. Select the option to automatically generate the NAT gateway in the Deploy the Network Security virtual appliance section or use these steps to manually deploy the NAT gateway.


  1. Navigate to NAT gateways+ Add.
  2. Enter the required information on the Basics tab.
  3. In the Outbound IP tab, select Public IP addresses or Public IP prefixes depending on your resources.
    • Public IP address: A single IP address
    • Public IP prefixes: A range of public IP addresses
  4. In the Subnet tab, select your Hub-VNet name, then select the management-subnet.
  5. Click Review + Create, and then click Create.

The management subnet can be associated after the NAT gateway is created by clicking the Subnet menu option from the NAT gateway details page.


Deploy the Network Security virtual appliance

The Network Security virtual appliance is available from the Azure Marketplace as a public offer. To deploy the Network Security virtual appliance, navigate to Azure Portal → Marketplace → Trend Micro Cloud One™ – Network Security.

Manually add virtual appliances to Cloud One if the Azure Marketplace deployment does not properly register the virtual appliance(s) to Network Security.

Gather the following information before you begin the deployment:


Note

Best practice is to copy and paste the exact names of the resource group, hub-VNet, and subnets.



  1. Log into Azure and select Create a resource (this will direct you to the Marketplace).
  2. Search for Trend Micro Network Security.
  3. Next to Select a plan, choose Scale Set VM in the dropdown menu.
  4. Click Create.
  5. Enter the following information in the Basics tab:
  6. Select the following information in the Networking tab:
    • Your virtual network.
    • All of the subnets you created in the inspection-VNet.
    • For NAT Gateway, either choose Create new to automatically create a new NAT gateway when you deploy the virtual appliance, or choose Select existing if you already manually created a NAT gateway.
  7. Enter or select the following information in the Advanced tab:
    • (Suggested) Keep the Boot diagnostics setting enabled.
    • Select your boot diagnostic account, or create a new one.
    • Enter the Log Analytics workspace ID and Primary Key in order to upload your logs to the Network Security management portal.
  8. Click Review + Create, and then click Deploy.


Create an outbound-only public load balancer

If you chose option 2 in the Internet connectivity notice section, add a public load balancer to your configuration to allow the Network Security virtual appliance to communicate with Cloud One – Network Security.

Step 1: Create a public load balancer

  1. Navigate to Load balancers+ Add.
  2. Configure the settings below, leaving the other settings in their default state.
    • Type: Public
    • SKU: Standard
    • Public IP address: Create new or use existing
    • Availability zone (create new IP option only): Zone-redundant
    • Choose public IP address (use existing IP option only): select an IP
  3. Click Review + Create and then click Create.

Step 2: Create a public backend pool

  1. In your public load balancer, select Backend pools.
  2. Click + Add.
  3. Configure the settings below, leaving the other settings in their default state.
    • Virtual network: Select your VNet
    • IP version: IPv4
    • Virtual machine scale set: Select your VMSS Network Security virtual appliance
    • IP address: Select the management port
  4. Click Add.

Step 3: Configure a public load balancer outbound rule

  1. In your public load balancer, select Outbound rules.
  2. Click + Add.
    • Frontend IP address: Create New or use existing
    • Protocol: All
    • Idle timeout: Set to 15 minutes
    • TCP reset: Enabled
    • Backend pool: <your backend pool>
    • Port allocation: Use the default number of outbound ports
  3. Click Add.

Learn more about testing the outbound connectivity.


Configure the Azure Firewall

After you create and deploy the Azure Firewall, make the following configuration changes. Learn more.

Note the Firewall IP information

Private and public IPs are assigned automatically after you create the firewall. Note the IP information for future use in the deployment process.

  1. Navigate to FirewallsAzureFirewall.
  2. Select Public IP Configuration.
  3. Write down the Private and Public IP addresses for the AzureFirewallSubnet.

Configure the Firewall rules

Configure the AzureFirewall NAT Rule (Ingress) and Network Rule (Egress).

Configure the NAT rule

  1. Navigate to FirewallsAzureFirewall.
  2. Select RulesNAT rule collection tab.
  3. Click + Add NAT rule collection.
  4. Enter a name and priority.
  5. Configure the NAT rule settings:
    • Name: Ingress
    • Protocol: TCP
    • Source type: IP address
    • Source: *
    • Destination address: <Public IP of the AzureFirewall>
    • Destination ports: 80
    • Translated address: <Private IP of your Workload VM>
    • Translated port: 80
  6. Click Add.

Configure the Network Rule

  1. Navigate to the Network rule collection tab and click + Add network rule collection.
  2. Add a name, priority, and action.
  3. Configure the NAT rule settings:
    • Name: Egress
    • Protocol: Any
    • Source type: IP address
    • Source: Your entire V-Net
    • Destination type: IP address
    • Destination address: *
    • Destination ports: *
  4. Click Add.


Configure route tables and rules

After the Network Security virtual appliance is deployed, add and configure the route tables and routes to place your virtual appliance in-line and begin inspecting traffic. The firewall rules are applied to the network traffic when it is routed to the firewall as the subnet default gateway.

The following information is required to complete this process:

Step 1: Create three route tables

  1. Navigate to Route tables and click + Add.
  2. Enter these values for each route table:
    • Table one: Firewall-rt
    • Table two: DataportB-rt
    • Table three: Spoke-rt
  3. Click Review + Create, and then click Create.
  4. Repeat this process for the remaining tables.

Step 2: Configure the route tables

  1. From the Route tables page, select the Firewall-rt table, then click Routes+ Add.
  2. Enter this information:
    • Name: toSpoke
    • Address prefix: <CIDR of the Spoke-VNet>
    • Next hop type: Virtual Appliance
    • Next hop address: <IP address of the internal load balancer>
    • Click OK.
  3. Add another route to the Firewall-rt.
    • Name: Default
    • Address prefix: 0.0.0.0/0
    • Next hop type: Internet
    • Click OK.
  4. Select the DataportB-rt table, then click Routes+ Add.
    • Name: Default
    • Address prefix: 0.0.0.0/0
    • Next hop: Virtual Appliance
    • Next hop address: <Private IP of AzureFirewall>
    • Click OK.
  5. Select the Spoke-rt table, then click Routes+ Add.
  6. Enter this information:
    • Name: toSpoke
    • Address prefix: <CIDR of the Spoke-VNet>
    • Next hop type: Virtual Appliance
    • Next hop address:<IP address of the internal load balancer>
    • Click OK.
  7. Add another route to the Spoke-rt table.
    • Name: toFirewall
    • Address prefix: <CIDR of AzureFirewallSubnet>
    • Next hop: Virtual Appliance
    • Next hop address: <IP address of the internal load balancer>
    • Click OK.
  8. Add another route to the Spoke-rt table.
    • Name: Default
    • Address prefix: 0.0.0.0/0
    • Next hop: Virtual Appliance
    • Next hop address: `<IP address of the internal load balancer>
    • Click OK.

Step 3: Associate the route tables to the related subnet

  1. Select your Spoke-rt table, then click Subnets+ Associate.
    • Virtual network: Spoke-VNet
    • Subnet: Workload1-subnet
  2. Select your Firewall-rt table, then click Subnets+ Associate.
    • Virtual network: <Your Hub-VNet>
    • Subnet: <AzureFirewallSubnet>
  3. Select your DataportB-rt table, then click Subnets+ Associate.
    • Virtual network: <Your Hub-VNet>
    • Subnet: <Sanitized-hub>