Network Configuration

Overview

Before creating the firewall VM, we need to configure the network interfaces properly. This guide will walk you through setting up a separate network bridge for your LAN traffic.

Network Architecture

Management Network (vmbr0)

Do Not Modify

The vmbr0 interface is your default management network bridge, configured during installation. This interface should not be modified as it provides:

• Management access to Proxmox web interface
• WAN connectivity for your environment
• Default route to the internet

Creating the LAN Bridge

Since vmbr0 handles WAN traffic, we need a separate bridge for LAN connectivity. This bridge will:

• Connect your firewall's LAN interface
• Provide network access for your virtual machines
• Create an isolated internal network

Step 1: Initialize Bridge Creation

Click the "Create" button in the network interface section:

Step 2: Configure Bridge Settings

Bridge Configuration

1. Name: We use vmbr2 in this guide (you can choose a different name if needed)
2. IPv4/CIDR: Set your desired LAN subnet IP address
   • This will be the Proxmox host's IP on the LAN network
   • Choose an IP that won't conflict with your firewall's LAN IP
3. Leave other settings at their defaults

Important

Do not configure a gateway on this bridge. Your management network (vmbr0) must remain the default route to maintain web interface access.

Step 3: Apply Configuration

After creating the bridge, you must apply the changes:

1. Review the pending changes carefully
2. Click "Apply Configuration"

A confirmation dialog will appear:

Network Bridge Usage

Your new bridge will be used for:

• OPNsense firewall LAN interface
• Virtual machine network connectivity
• Internal network communication

Next Steps

Once your network bridges are configured, you can proceed with creating and configuring your firewall VM.