configuring-pfsense-firewall-rules

name	configuring-pfsense-firewall-rules
description	Configures pfSense firewall rules, NAT policies, VPN tunnels, and traffic shaping to enforce network segmentation, control traffic flow, and protect internal network zones in enterprise and small-to-medium business environments.
domain	cybersecurity
subdomain	network-security
tags	["network-security","pfsense","firewall","nat","network-segmentation"]
version	1.0
author	mahipal
license	Apache-2.0
nist_csf	["PR.IR-01","DE.CM-01","ID.AM-03","PR.DS-02"]

Configuring pfSense Firewall Rules

When to Use

• Deploying a perimeter or internal firewall to segment and protect network zones (DMZ, internal, guest, IoT)
• Creating granular access control rules to restrict traffic between VLANs and network segments
• Configuring NAT rules for port forwarding to internal services exposed to the internet
• Setting up site-to-site or remote access VPN tunnels using IPsec or OpenVPN
• Implementing traffic shaping and bandwidth management for quality-of-service requirements

Do not use as a substitute for host-based firewalls on individual systems, for SSL/TLS deep packet inspection without dedicated hardware acceleration, or as the sole security control without complementary IDS/IPS.

Prerequisites

• pfSense 2.7+ installed on dedicated hardware or virtual machine with at least two network interfaces
• Access to the pfSense WebConfigurator (default: https://192.168.1.1)
• Network topology diagram showing all interfaces, VLANs, and desired traffic flow
• DNS and DHCP configuration planned for each network zone
• Understanding of TCP/IP, NAT, and stateful firewall concepts

Workflow

Step 1: Configure Network Interfaces and VLANs

Access the pfSense WebConfigurator and define interfaces:

Navigate: Interfaces > Assignments

WAN Interface (igb0):
  - Type: DHCP or Static IP from ISP
  - Block private networks: Enabled
  - Block bogon networks: Enabled

LAN Interface (igb1):
  - IPv4: 10.10.1.1/24
  - Description: CORPORATE_LAN

Create VLANs:
  Navigate: Interfaces > VLANs > Add
  - VLAN 10 on igb1: DMZ (10.10.10.1/24)
  - VLAN 20 on igb1: SERVERS (10.10.20.1/24)
  - VLAN 30 on igb1: GUEST (10.10.30.1/24)
  - VLAN 40 on igb1: IOT (10.10.40.1/24)

Assign VLANs:
  Navigate: Interfaces > Assignments > Add each VLAN
  Enable each interface and assign the gateway IP

Step 2: Configure DHCP and DNS for Each Zone

Navigate: Services > DHCP Server

CORPORATE_LAN (10.10.1.0/24):
  Range: 10.10.1.100 - 10.10.1.200
  DNS: 10.10.20.10 (internal DNS server)
  Gateway: 10.10.1.1

DMZ (10.10.10.0/24):
  Range: 10.10.10.100 - 10.10.10.200
  DNS: 10.10.20.10
  Gateway: 10.10.10.1

GUEST (10.10.30.0/24):
  Range: 10.10.30.100 - 10.10.30.200
  DNS: 1.1.1.1, 8.8.8.8 (public DNS only)
  Gateway: 10.10.30.1

Navigate: Services > DNS Resolver
  Enable DNS Resolver on all interfaces except GUEST
  Enable DNSSEC
  Configure forwarding to upstream DNS servers

Step 3: Create Firewall Rule Aliases

Navigate: Firewall > Aliases

RFC1918_Networks:
  Type: Network
  Values: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16

WebPorts:
  Type: Port
  Values: 80, 443

ManagementPorts:
  Type: Port
  Values: 22, 3389, 5900

CriticalServers:
  Type: Host
  Values: 10.10.20.10, 10.10.20.11, 10.10.20.12

BlockedCountries:
  Type: URL Table
  URL: https://www.ipdeny.com/ipblocks/data/aggregated/cn-aggregated.zone
  Update: 24 hours