This project is typically used with a Linux gateway (often a Raspberry Pi) to bridge the RF24 mesh/network to a normal IP network using a TUN/TAP interface.

If you only want node-to-node demos, start with the Headless examples first. If you want to reach services on your LAN (or run services on RF24 nodes and access them from LAN clients), set up the gateway.

What the gateway does

Runs an RF24 radio + networking stack on Linux
Creates a virtual network interface (TUN/TAP) that looks like a normal NIC to Linux
Routes IP traffic between:
- RF24 nodes (RF24Ethernet)
- your LAN (eth0/wlan0)

Prerequisites

A Linux machine (Raspberry Pi recommended)
A compatible RF24 radio connected to the Linux machine (SPI wiring + stable power)
This repo’s Arduino sketches running on nodes (RF24 + RF24Network + RF24Mesh + RF24Ethernet)

Note: The gateway software is provided by nRF24/RF24Gateway. Docs: https://nrf24.github.io/RF24Gateway/

Install RF24* libraries and build RF24Gateway (Raspberry Pi)

Download and run the installer script (builds/installs the required RF24* libraries):

wget https://raw.githubusercontent.com/nRF24/.github/main/installer/install.sh

chmod +x install.sh

./install.sh
Build and run the RF24Gateway ncurses example:

cd rf24libs/RF24Gateway/examples/build

make

cd ncurses

./RF24Gateway_ncurses

Quick checklist (sanity)

Before configuring routing, make sure:

The radio is detected and can communicate (gateway logs show packets / node activity)
The TUN/TAP interface exists and is UP
Linux has a route for the RF24 subnet via that interface

Step 1: Create/enable a TUN interface

RF24Gateway can create the interface automatically when running as root. If running unprivileged, you may need to create the TUN interface manually:

# Create a persistent TUN device named tun_nrf24, owned by user "pi"
sudo ip tuntap add dev tun_nrf24 mode tun user pi multi_queue
 
# Assign the gateway-side IP for the RF24 subnet
sudo ip addr add 10.10.2.2/24 dev tun_nrf24
 
# Bring it up
sudo ip link set tun_nrf24 up

Verify:

ip addr show tun_nrf24
ip link show tun_nrf24
ip route | grep 10.10.2.0/24

Step 2: Enable IP forwarding

If you want traffic to route between interfaces (tun_nrf24 <-> eth0/wlan0):

sudo sysctl -w net.ipv4.ip_forward=1

To make it persistent, add to /etc/sysctl.conf:

net.ipv4.ip_forward=1

Step 3: Add routes (LAN <-> RF24 subnet)

Usually Linux learns the connected route once you assign the tun_nrf24 address, but you can confirm:

ip route

You should see something like:

10.10.2.0/24 dev tun_nrf24 proto kernel scope link src 10.10.2.2

If your LAN clients need to reach RF24 nodes, you have two common options:

Option A: Add a static route on your router (preferred)

Add a route on your LAN router:

Destination: 10.10.2.0/24
Next hop: <gateway-lan-ip> (the Raspberry Pi’s IP on your LAN)

This avoids NAT and keeps the network transparent.

Option B: NAT (masquerade) traffic from RF24 to LAN/Internet

This is easier when you cannot change the router.

Example (replace wlan0 with your LAN-facing interface):

sudo iptables -t nat -A POSTROUTING -s 10.10.2.0/24 -o wlan0 -j MASQUERADE

If you want this to persist, use your distro’s preferred firewall persistence mechanism (e.g., iptables-persistent, nftables, or a systemd unit).

Optional: TCP buffer tuning (throughput)

To maximize throughput between Raspberry Pi or other Linux devices, you can set TCP buffer sizes. To make these changes permanent, edit /etc/sysctl.conf.

sudo sysctl net.ipv4.tcp_wmem="1500 1500 1500"

sudo sysctl net.ipv4.tcp_rmem="1500 1500 1500"

Warning: These commands can severely impact other network functionality. Run sudo sysctl net.ipv4.tcp_wmem and sudo sysctl net.ipv4.tcp_rmem first to record defaults so they can be restored.

Step 4: Test connectivity

From the gateway

Ping a node IP:

ping 10.10.2.3

From a LAN machine (if routing is configured)

Ping the same node:

ping 10.10.2.3

Watch traffic on the tunnel

On the gateway:

sudo tcpdump -ni tun_nrf24

You should see ICMP/TCP/UDP packets when nodes communicate.

Common problems

TUN interface is up but nothing responds

Wrong subnet or IP mismatch between sketches and gateway
RF24Gateway is running but not attached to the same RF24 channel/addressing as nodes
RF24 radio power problems (brownouts) or SPI wiring issues

Checks

tcpdump -ni tun_nrf24 (do packets appear at all?)
RF24Gateway output/logs (do nodes join mesh / show activity?)

Nodes can talk to gateway but LAN cannot reach nodes

Missing route on router (Option A) or missing NAT rule (Option B)
net.ipv4.ip_forward=0
Firewall blocking forwarding

Checks

sysctl net.ipv4.ip_forward
ip route
sudo iptables -S and sudo iptables -t nat -S (or nft list ruleset)

DNS works on LAN but not on nodes

Nodes need a reachable DNS server IP (often your router)
uIP: UDP may need to be manually enabled on the node for DNS to work
lwIP: UDP is enabled by default
Gateway must route UDP/53 properly (and not block it)
Try the Getting_Started_SimpleClient_Mesh_DNS example first

Notes

Keep RF24 subnets small and simple at first (one /24).
Once you have stable ping, then add TCP services (HTTP/MQTT) to reduce variables.
If you have performance issues, prefer lwIP on faster MCUs (configured via RF24BoardConfig.h).