Transparent Firewall with OPNsense on Proxmox

🧱 STEP 1: Create the OPNsense VM in Proxmox

💡 Goal:

Install OPNsense with 2 network interfaces in bridge mode.

🛠 What You Need:

• ✅ OPNsense ISO: https://opnsense.org/download
• ✅ Proxmox running on PowerEdge server (whatever you have as infrastucture)
• ✅ Internet access for ISO download & updates

🔧 Steps:

🖼️ 1. Upload the OPNsense ISO to Proxmox

• Go to Proxmox Web UI → local → ISO Images → Upload
• Upload the OPNsense ISO you downloaded

🖥️ 2. Create the VM

• Node → Right-click → Create VM
• General:
  • Name: opnsense-fw
• OS:
  • Use the uploaded OPNsense ISO
• System:
  • BIOS: Default (SeaBIOS)
  • Machine: i440fx (or default)
• Hard Disk:
  • 10–16 GB is enough
• CPU:
  • 1 core (2 if available)
• Memory:
  • 1024 MB (1 GB) minimum
• Network:
  • Add 2 NICs, both attached to bridge interfaces
    • WAN (e.g., vmbr0) connects to your LAN/internet
    • LAN (e.g., vmbr1) connects to test VMs

💡 Use VirtIO or Intel E1000 as NIC model (both work fine)

💾 3. Start the VM and Launch Console

• Boot from ISO
• Choose Install OPNsense
• Follow the installer steps:
  • Accept defaults
  • Password: choose a secure one
  • Assign interfaces (usually em0 = WAN, em1 = LAN)

✅ Once OPNsense is installed and running, we’ll:

• Assign LAN a temporary IP to access the web UI
• Log in via browser
• Set up bridge mode manually inside OPNsense

Then configure bridge setup inside OPNsense next on the UI of opnsense.