Raspberry Pi as a Router: OPNsense vs OpenWrt Setup Guide

When my ISP-provided router dropped connections for the third time in a week, I decided enough was enough. Consumer-grade routers sacrifice features and reliability for convenience. Building a raspberry pi router seemed like the perfect solution, offering complete control over my network while teaching me about routing, firewalls, and network security.

But here’s what I discovered after extensive testing: not all router software works equally well on Pi hardware. If you’ve searched for opnsense raspberry pi hoping to run that popular firewall, you need to understand some important limitations before investing time and money. This guide compares both options honestly and walks you through setting up the solution that actually works best on Raspberry Pi hardware.

Understanding Router Software Options

Before diving into installation, understanding what each platform offers helps you make the right choice for your network needs.

What is OpenWrt?

OpenWrt is an open-source Linux distribution specifically designed for embedded devices and routers. Originally created to replace proprietary firmware on consumer routers, it has evolved into a full-featured routing platform with official Raspberry Pi support.

OpenWrt Feature	Description
Operating System	Linux-based
Target Hardware	Embedded devices, routers, SBCs
Raspberry Pi Support	Official, all models
Web Interface	LuCI
Package Manager	opkg (legacy) / apk (24.10+)
Resource Usage	Very lightweight

What is OPNsense?

OPNsense is a FreeBSD-based firewall and routing platform forked from pfSense. It offers enterprise-grade features including intrusion detection, VPN support, traffic shaping, and advanced monitoring tools.

OPNsense Feature	Description
Operating System	FreeBSD-based
Target Hardware	x86-64 systems
Raspberry Pi Support	Not officially supported
Web Interface	Custom GUI
Package Manager	pkg
Resource Usage	Moderate to heavy

The Critical Difference: Pi Compatibility

Here’s the uncomfortable truth that many articles gloss over: OPNsense does not officially support ARM processors or Raspberry Pi hardware. The OPNsense team considered ARM support but concluded it would create a support nightmare due to the variety of ARM boards requiring special configurations.

Platform Support Comparison

Aspect	OpenWrt	OPNsense
Raspberry Pi 5	Supported (SNAPSHOT)	Not supported
Raspberry Pi 4	Fully supported	Not supported
Raspberry Pi 3	Fully supported	Not supported
Official ARM Images	Yes	No
Community ARM Builds	Extensive	Limited, experimental
Update Path	Standard updates	Requires full reinstall

While some enthusiasts have created unofficial OPNsense builds for Raspberry Pi, these lack official support, may break with updates, and require significant technical expertise to maintain. For production use on Pi hardware, OpenWrt remains the practical choice.

If you specifically need OPNsense features, consider running it on a mini-PC with x86-64 hardware, which provides full compatibility and better performance for firewall workloads.

Hardware Requirements for a Raspberry Pi Router

Building an effective raspberry pi router requires understanding the hardware limitations and how to work around them.

The Single Ethernet Port Problem

Every Raspberry Pi model includes only one Ethernet port. Routers need at least two network interfaces (WAN and LAN). Solutions include:

Solution	Speed	Cost	Complexity
USB Ethernet Adapter	Up to 2.5 Gbps	$12-30	Low
USB WiFi Adapter	Variable	$15-40	Medium
PCIe HAT (Pi 5 only)	Up to 2.5 Gbps	$25-50	Medium
VLAN with Managed Switch	Network speed	$30-60	High

Recommended Hardware by Pi Model

Model	RAM	Ethernet	USB Ports	Router Suitability
Raspberry Pi 5	4-8GB	1 Gbps	2× USB 3.0	Excellent
Raspberry Pi 4	2-8GB	1 Gbps	2× USB 3.0	Very Good
Raspberry Pi 3B+	1GB	300 Mbps	4× USB 2.0	Limited
Raspberry Pi Zero 2W	512MB	None	1× USB 2.0	Travel router only

Essential Hardware Shopping List

Component	Purpose	Recommended
Raspberry Pi 5 or 4	Router platform	4GB+ RAM
USB 3.0 Ethernet Adapter	Second NIC	TP-Link UE300 (RTL8153)
Quality microSD Card	OS storage	32GB+ Class A2
Adequate Power Supply	Stable operation	Official 27W (Pi 5) / 15W (Pi 4)
Case with Cooling	Thermal management	Active cooling recommended
Optional: USB WiFi Adapter	Access point	MT7921/RTL8812AU chipset

USB Ethernet Adapter Recommendations

Adapter	Chipset	Speed	OpenWrt Support	Price
TP-Link UE300	RTL8153	1 Gbps	Excellent	~$12
Cable Matters	RTL8153	1 Gbps	Excellent	~$15
Plugable 2.5G	RTL8156	2.5 Gbps	Good (needs driver)	~$25
Anker USB-C	RTL8153	1 Gbps	Excellent	~$20

The RTL8153 chipset offers the best compatibility with OpenWrt. The RTL8156 for 2.5 Gbps speeds requires additional driver configuration but works well once set up.

OpenWrt Installation on Raspberry Pi

Setting up OpenWrt provides the most reliable raspberry pi router experience. Follow these steps for a successful installation.

Step 1: Download the Correct Image

Visit the official OpenWrt download page and select your Pi model:

Pi Model	Image Type	Architecture
Raspberry Pi 5	SNAPSHOT	bcm27xx/bcm2712
Raspberry Pi 4	Stable (24.10)	bcm27xx/bcm2711
Raspberry Pi 3	Stable (24.10)	bcm27xx/bcm2710
Raspberry Pi 2	Stable (24.10)	bcm27xx/bcm2709

Download the factory image (ext4 or squashfs). For beginners, squashfs provides a smaller footprint and reset capability.

Step 2: Flash the Image

Use Raspberry Pi Imager or balenaEtcher to write the image to your microSD card. The process takes approximately 5-10 minutes depending on card speed.

Step 3: Initial Boot and Connection

Insert the microSD card into your Pi and connect:

• Power supply
• Ethernet cable from your computer to the Pi’s built-in port

Do not connect the USB Ethernet adapter yet. Wait approximately 60 seconds for the first boot to complete.

Step 4: Access the Web Interface

Open a browser and navigate to:

http://192.168.1.1

You’ll see the LuCI web interface. The default login has no password for root, so your first task is setting one.

Step 5: Install USB Ethernet Drivers

This is the critical step many guides miss. OpenWrt doesn’t include USB Ethernet drivers by default. You need to install them before your USB adapter will work.

Temporarily connect the WAN port to your existing router to get internet access, then install via System → Software:

Package	Purpose
kmod-usb-net	USB networking support
kmod-usb-net-rtl8152	RTL8152/8153/8156 driver
kmod-mii	MII support
luci-proto-wireguard	WireGuard VPN (optional)

Alternatively, use the OpenWrt Firmware Selector to build a custom image with these packages pre-installed.

Step 6: Configure Network Interfaces

After installing drivers and rebooting:

1. Navigate to Network → Interfaces
2. The built-in port (eth0) defaults to LAN
3. Add the USB adapter (eth1) as WAN
4. Configure WAN with DHCP client or PPPoE as required
5. Save and apply changes

Step 7: Configure Firewall and DHCP

OpenWrt automatically configures basic firewall rules. Verify settings under:

• Network → Firewall
• Network → DHCP and DNS

Performance Expectations for Raspberry Pi Router

Understanding throughput capabilities helps set realistic expectations for your raspberry pi router.

Measured Performance Results

Test Scenario	Pi 4	Pi 5 (Expected)
Plain routing (NAT)	~940 Mbps	~1000 Mbps
WireGuard VPN	~840 Mbps	~900+ Mbps
OpenVPN	~200-300 Mbps	~400-500 Mbps
SQM (Traffic Shaping)	~500-700 Mbps	~800+ Mbps
WiFi AP (USB adapter)	~300-400 Mbps	~400-500 Mbps

Performance Optimization Tips

Optimization	Impact	Difficulty
Enable software flow offload	+20-30% throughput	Easy
Use irqbalance	Better multi-core usage	Easy
Disable IPv6 (if unused)	Slight improvement	Easy
Use SSD instead of SD card	Better responsiveness	Medium
Custom kernel compilation	Marginal gains	Advanced

When OPNsense Makes Sense (Alternative Hardware)

If you need OPNsense features like Suricata IDS, advanced traffic analysis, or enterprise-grade VPN, consider alternative hardware instead of fighting Raspberry Pi limitations.

OPNsense Hardware Alternatives

Device Type	Cost	Performance	Power Usage
Used Mini PC (i5)	$80-150	Excellent	15-35W
Protectli Vault	$300-500	Excellent	10-15W
Qotom/Topton Mini PC	$150-250	Very Good	10-20W
Virtual Machine	Free (with host)	Varies	Shared

OPNsense vs OpenWrt Feature Comparison

Feature	OpenWrt	OPNsense
Stateful Firewall	Yes	Yes
NAT/Port Forwarding	Yes	Yes
VLAN Support	Yes	Yes
WireGuard VPN	Yes	Yes
OpenVPN	Yes	Yes
Intrusion Detection (IDS)	Limited	Suricata/Snort
Traffic Shaping	SQM	Traffic Shaper
Ad Blocking	AdGuard Home/PiHole	Plugins
Web Filtering	Limited	Comprehensive
High Availability	No	Yes
Captive Portal	Yes	Yes
GUI Complexity	Simple	Advanced

For most home users, OpenWrt provides everything needed. OPNsense excels in environments requiring advanced security monitoring and enterprise features.

Common Use Cases for Raspberry Pi Router

Travel Router

A compact raspberry pi router excels as a travel companion:

• Connect to hotel WiFi as client
• Broadcast your own secure WiFi network
• Run VPN to encrypt all traffic
• Share single-device connections with multiple devices

Network Segmentation

Isolate IoT devices from your main network:

• Create separate VLANs for different device types
• Apply different firewall rules per network
• Monitor traffic from potentially insecure devices

VPN Gateway

Route all traffic through VPN:

• WireGuard for high performance
• OpenVPN for broader compatibility
• Split tunneling for selective routing

Ad Blocking Router

Combine routing with network-wide ad blocking:

• Install AdGuard Home as OpenWrt package
• Block ads at DNS level for all devices
• No per-device configuration needed

Useful Resources

Resource	URL	Description
OpenWrt Downloads	downloads.openwrt.org	Official firmware images
OpenWrt Firmware Selector	firmware-selector.openwrt.org	Custom image builder
OpenWrt Wiki	openwrt.org/docs	Documentation
OpenWrt Forum	forum.openwrt.org	Community support
OPNsense Downloads	opnsense.org/download	x86-64 images only
OPNsense Docs	docs.opnsense.org	Official documentation
Home Network Guy	homenetworkguy.com	Excellent tutorials
Pi Router Forum	forums.raspberrypi.com	Pi-specific discussions
PiFi Project	github.com/pifi	Pre-built OpenWrt for Pi

Advanced OpenWrt Configuration

Once your basic raspberry pi router is working, these advanced configurations unlock additional capabilities.

Setting Up WireGuard VPN Server

WireGuard provides excellent VPN performance on Raspberry Pi hardware:

Configuration Step	Purpose
Install luci-proto-wireguard	Adds WireGuard support
Generate keypairs	Create server and client keys
Configure interface	Set listening port and IP range
Add peers	Configure client devices
Enable firewall rules	Allow VPN traffic

Performance reaches 800+ Mbps on Pi 4, making it suitable for remote access even with fast internet connections.

Implementing Traffic Shaping with SQM

Smart Queue Management eliminates bufferbloat and improves latency for gaming and video calls:

SQM Setting	Recommended Value
Download Speed	85-95% of measured
Upload Speed	85-95% of measured
Queue Discipline	cake
Link Layer	Ethernet with overhead

Install the luci-app-sqm package and configure through Network → SQM QoS. Test results at dslreports.com/speedtest before and after to verify improvement.

Adding Guest Network

Isolate visitors from your main network:

Step	Action
Create new interface	guest with separate subnet
Configure DHCP	Separate pool for guests
Set firewall zone	guest zone with limited access
Block LAN access	Prevent guest-to-LAN traffic
Add WiFi SSID	Broadcast separate network name

Monitoring and Statistics

Track network usage with built-in tools:

Tool	Package	Purpose
Netdata	netdata	Real-time monitoring
vnStat	vnstat	Bandwidth statistics
Collectd	luci-app-statistics	Graphing and history
Bandwidthd	bandwidthd-sqlite	Per-host tracking

Troubleshooting Common Issues

USB Adapter Not Detected

Symptom	Cause	Solution
No eth1 interface	Missing drivers	Install kmod-usb-net packages
Adapter disconnects	Power issue	Use powered USB hub
Slow speeds	USB 2.0 port	Ensure USB 3.0 connection

Can’t Access Web Interface

Symptom	Cause	Solution
Connection refused	Wrong IP	Try 192.168.1.1
Timeout	Network config	Connect directly to LAN port
Password unknown	Locked out	Reflash and start fresh

Poor Performance

Symptom	Cause	Solution
Slow throughput	Software NAT	Enable flow offload
High latency	CPU overload	Reduce active services
Packet loss	Thermal throttling	Improve cooling

Frequently Asked Questions

Can I really run OPNsense on a Raspberry Pi?

While some community members have created experimental OPNsense builds for Raspberry Pi, these are unofficial, unsupported, and problematic for production use. OPNsense is built on FreeBSD for x86-64 architecture, not ARM. Every update requires a complete reinstallation, WiFi support is limited, and performance is suboptimal. For Raspberry Pi, OpenWrt provides a far better experience. If you specifically need OPNsense features, invest in a compatible mini-PC instead.

How fast can a Raspberry Pi router actually be?

A properly configured Raspberry Pi 4 with OpenWrt achieves approximately 940 Mbps for plain NAT routing and 840 Mbps for WireGuard VPN traffic. The Pi 5 should exceed these numbers. These speeds satisfy most home internet connections. However, if you have 2.5 Gbps or faster internet, the Pi becomes a bottleneck. For gigabit connections, a Pi 4 or 5 works excellently as a raspberry pi router.

Is Raspberry Pi reliable enough for a primary router?

With proper hardware (quality power supply, adequate cooling, good SD card), a Raspberry Pi runs reliably for years. Many users report uptimes measured in months. The primary failure point is SD card wear from constant writes. Using an SSD via USB or limiting logging significantly improves longevity. For mission-critical applications, having a backup configuration ready makes recovery quick if issues occur.

What USB Ethernet adapter should I buy?

For proven OpenWrt compatibility, buy adapters using the Realtek RTL8153 chipset. The TP-Link UE300 and Cable Matters adapters work immediately without additional configuration. If you need 2.5 Gbps speeds, RTL8156-based adapters work but require installing an additional driver package. Avoid ASIX-based adapters as they’ve had historical compatibility issues with OpenWrt.

Should I use OpenWrt or just set up Pi as an access point?

If you only need WiFi coverage extension, a simple access point configuration using hostapd on Raspberry Pi OS suffices. However, if you want routing capabilities (NAT, firewall, VPN, traffic shaping), OpenWrt provides these features with a mature, well-tested codebase. OpenWrt also handles multiple network interfaces, DHCP, DNS, and firewall rules in an integrated package that would require significant manual configuration otherwise.

Making Your Decision

For a raspberry pi router project, OpenWrt stands as the clear winner. It offers official Raspberry Pi support across all models, a lightweight footprint suited to the hardware, and a massive community providing ongoing development and support.

If your heart is set on opnsense raspberry pi, understand that you’re fighting against the platform’s design. Consider either OpenWrt on Pi (which provides most features you’d want) or OPNsense on a proper x86 mini-PC (which provides the full experience the developers intended).

Either path leads to a more capable, controllable network than any consumer router provides. The learning experience alone makes the project worthwhile, and the ongoing control over your network security proves invaluable as smart home devices and IoT equipment continue multiplying.

Start with OpenWrt on a Pi 4 or 5, get comfortable with the fundamentals, then expand from there. Your network will thank you.

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