Secure Pi SP2302 now supports dual Ethernet interfaces using the WIZ850io module (powered by the W5500 SPI-based Ethernet chip). This guide shows how to:

• Install iperf3from source
• Modify the linker path to fix shared library issues
• Run iperf to test bandwidth between eth1 (W5500) and a PC server

Requirements

• SP2302 board with WIZ850io module properly connected via SPI
• Dual port firmware flashed and eth1 configured
• A Linux or Windows PC on the same network
• Internet access for SP2302 (at least temporarily for cloning GitHub)

Step 1: Install iperf3 from GitHub on SP2302

1.1 Update system & install build tools

bash

sudo apt update
sudo apt install git build-essential autoconf automake libtool -y

1.2 Clone and compile iperf3

bash

git clone https://github.com/esnet/iperf.git
cd iperf
./configure
make
sudo make install

iperf3 binary and required libraries to /usr/local/lib.

Step 2: Fix libiperf.so.0 Linker Issue

You may encounter this error:

bash


iperf3: error while loading shared libraries: libiperf.so.0: cannot open shared object file

2.1 Create a linker config for /usr/local/lib

bash

echo "/usr/local/lib" | sudo tee /etc/ld.so.conf.d/iperf3.conf

2.2 Update linker cache

bash

sudo ldconfig

✅ Verify

bash

iperf3 --version

Should show:

nginx

iperf 3.x

Step 3: Set Up iperf3 Server on PC

On Your Linux/Mac/Windows PC:

iperf3>span class="md-plain"> (if not already):

bash

sudo apt install iperf3       # On Linux
brew install iperf3           # On macOS

Run it as a server:

bash

iperf3 -s

Leave this terminal open — it waits for incoming tests.

Step 4: Test from SP2302 Client (W5500 via eth1)

4.1 Ensure eth1 has a valid IP

bash

ip addr show eth1

If not, apply your netplan or assign a static IP.

4.2 Run iperf test via eth1

bash

iperf3 -c <PC_IP> -B <SP2302_eth1_IP>

For example:

bash

iperf3 -c 192.168.1.100 -B 192.168.1.50

Testing Output:

bash

iperf3 -c 10.0.1.202 -B 10.0.1.69

From PC:

From SP2302:

Step 5: Optional - Reverse Direction Test

From PC:

bash

iperf3 -c 192.168.1.50

Testing Output:

bash

iperf3 -c 10.0.1.69

From PC:

From SP2302:

This checks inbound performance to the SP2302 over W5500.

Summary

Step	Command/Action	Purpose
Clone & build iperf3	git clone, make install
Fix linker error	ldconfig with /usr/local/lib	Ensure dynamic lib loading
Start PC server	iperf3 -s	PC listens for traffic
Run client test	iperf3 -c -B	Test bandwidth from SP2302
Confirm results	Output with Mbits/sec	Network verified over W5500

Notes

• W5500 uses SPI — performance will not match native Gigabit Ethernet, but it's excellent for secondary/backhaul roles.
• Consider shielding and good power for SPI stability.