What is Smoothwall Express Firewall and Setting It Up on VMware ESXi 4.1

What is a Firewall?

A firewall is a security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. Its primary purpose is to create a barrier between your internal network and potential threats from the outside, such as hackers or malicious software. Firewalls can either be hardware devices, software applications, or a combination of both.

Introducing Smoothwall Express

Smoothwall Express is an open-source firewall distribution built on the GNU/Linux operating system. Designed for ease of use, it allows users to set up a firewall without extensive knowledge of Linux. It’s managed through a web-based interface, making it accessible for a wide range of users. Smoothwall Express supports various configurations, including Green (internal network), Red (external/internet), Orange (demilitarized zone, DMZ), and Purple (wireless network), to secure diverse network setups.

Smoothwall Express provides:

• Complete isolation of your internal network by stopping all incoming traffic unless it’s a direct response to an outgoing request.
• Flexibility to add services like VPNs, DHCP, or DNS, with minimal resource requirements.
• Automatic blocking of unauthorized access, enhancing the security of small to medium-sized networks.

Why Use Smoothwall Express?

Smoothwall Express is cost-effective, thanks to its open-source nature, and powerful enough to serve small and home office networks. It’s ideal for environments that require a straightforward firewall without the overhead of complex enterprise solutions. With Smoothwall Express, you gain the benefits of a dedicated firewall by using even an older PC, which can function solely as a firewall appliance.

Setting Up Smoothwall Express on VMware ESXi 4.1

Using VMware ESXi 4.1 to virtualize Smoothwall Express allows you to harness the firewall’s capabilities without dedicated hardware. Here’s a step-by-step guide to setting it up on VMware ESXi 4.1.

1. Download Smoothwall Express ISO

• Go to smoothwall.org and download the ISO file for Smoothwall Express 3.0, which is compatible with older hardware and virtualized environments.

2. Prepare VMware ESXi 4.1 for Smoothwall Express

• Ensure that you have VMware ESXi 4.1 installed and accessible via the vSphere Client.
• Log in to the vSphere Client, navigate to your datacenter, and select the host on which you want to install Smoothwall Express.

3. Create a New Virtual Machine for Smoothwall Express

• In the vSphere Client, click New Virtual Machine and choose Custom to manually configure it for Smoothwall.
• Name the VM (e.g., “Smoothwall Express”) and select the Linux OS family with the Other Linux 2.6.x Kernel (32-bit) option.
• Allocate resources:
  • Memory: 128MB minimum, but ideally 256MB to ensure smooth operation.
  • CPU: 1 vCPU is sufficient for a basic firewall setup.
• Configure the Hard Disk:
  • Create a 2GB virtual hard disk, as Smoothwall Express does not require extensive storage space.
• Network Adapters:
  • Add at least two network adapters. Assign one as your Green (internal) network and the other as your Red (external/internet) network. You may add additional interfaces if you plan to configure DMZ (Orange) or Wireless (Purple) zones.

4. Attach the Smoothwall Express ISO to the VM

• Under CD/DVD Drive settings, select the Datastore ISO File option, and locate the Smoothwall Express ISO you uploaded to the datastore.
• Ensure that the Connect at Power On option is checked, so the ISO loads when the VM starts.

5. Boot and Install Smoothwall Express

• Power on the VM and open the console.
• Follow these installation steps:
  1. When prompted, press Enter to start the installation.
  2. Accept the license agreement and proceed.
  3. Select the target hard disk (the virtual disk created earlier) and confirm any prompts to erase data.
  4. Configure your keyboard and set the hostname (e.g., “smoothwall”).
  5. Choose the Default Security Policy (Open, Half-Open, or Closed) based on your needs. A Half-Open policy allows most outbound requests, blocking only harmful ones, making it a secure choice for general use.
  6. Continue with the installation, following prompts to configure network cards.

6. Network Configuration

• Assign network interfaces according to the setup:
  • Green Interface: Connects to your internal network.
  • Red Interface: Connects to the internet or external network.
• If you have additional interfaces, configure Orange (DMZ) for servers that need external access or Purple for a separate wireless network.

7. Finalizing Configuration

• Set up IP addresses for the Green network and configure the Red network for your internet connection (using DHCP or Static IP depending on your ISP).
• Set DNS and Gateway settings to match your ISP or internal network settings.

8. Accessing Smoothwall Express

• Once installed, you can access the Smoothwall Express web interface from any browser on the Green network by navigating to https://[Smoothwall_IP]:441.
• Log in using the admin username and the password set during installation.

9. Post-Installation Setup

• From the web interface, complete any additional configurations, such as:
  • DHCP settings if you want Smoothwall to assign IPs to devices on your Green network.
  • Web proxy settings if required by your ISP.
  • Update settings to ensure your Smoothwall installation is up to date.

Smoothwall Express: A Cost-Effective, Virtualized Firewall

Setting up Smoothwall Express on VMware ESXi 4.1 provides a robust solution for securing your network. This configuration not only leverages older hardware efficiently but also ensures your network is protected through open-source flexibility and the power of virtualization.