如何使用Wireshark嗅探LoRaWAN数据包？CC2531 USB dongle能否用于LoRa及实现方法

Great questions! Let's break this down step by step to help you get set up.

Sniffing LoRaWAN Packets with Wireshark #

Wireshark doesn't have built-in RF reception capabilities, so you'll need to pair it with LoRa-compatible hardware and custom firmware to feed packet data into the tool. Here's how to make it work:

1. Repurpose Your Existing Hardware #

You already have RFM9X (LoRa) modules from your Arduino/ESP32 projects—perfect! You can use one of these paired with an ESP32 or Arduino board as your passive sniffing device. No need to buy new hardware here.

2. Flash a LoRa Sniffer Firmware #

Program your RFM9X + ESP32/Arduino to act as a sniffer with these steps:

• Use a customizable firmware like LoRaWAN_Sniffer (via Arduino IDE) that puts the RFM9X into continuous receive mode.
• Configure the firmware to match the exact LoRaWAN parameters of your target network:
  • Frequency (e.g., 868MHz for EU regions, 915MHz for US)
  • Spreading Factor (SF7 to SF12)
  • Bandwidth (common options: 125kHz, 250kHz)
  • Coding Rate (e.g., 4/5)
• Set the firmware to output raw packet frames or parsed LoRaWAN data over the serial port to your computer.

3. Pipe Serial Data into Wireshark #

Once your sniffer is sending data over serial, connect it to Wireshark using one of these methods:

• Option 1: Use Tshark (Wireshark's command-line tool)
  • First, identify your serial port (e.g., /dev/ttyUSB0 on Linux, COM3 on Windows).
  • Run this command to capture serial data and save it as a PCAP file:

    tshark -i /dev/ttyUSB0 -b filesize:10000 -w lora_capture.pcap
    

  • Open the saved lora_capture.pcap file directly in Wireshark.
• Option 2: Use Wireshark's Built-in Serial Capture
  • Go to Capture > Options > Manage Interfaces > Serial, select your port, and start capturing directly.
• Enable LoRaWAN Parsing
  • In Wireshark, navigate to Edit > Preferences > Protocols > LoRaWAN and ensure the protocol is enabled. Wireshark will automatically parse valid LoRaWAN frames if the captured data is formatted correctly.

Can CC2531 USB Dongle Capture LoRa Packets? #

Short answer: No, it cannot. Here's the breakdown of why:

• Frequency Mismatch: The CC2531 is designed exclusively for the 2.4GHz ISM band (used by ZigBee, Bluetooth, and Wi-Fi). LoRa operates in sub-GHz bands (433MHz, 868MHz, 915MHz, etc.)—the CC2531 has no hardware support for these frequencies.
• Modulation Incompatibility: LoRa uses a proprietary spread-spectrum modulation scheme, while the CC2531 is built for IEEE 802.15.4's O-QPSK modulation. It can't demodulate LoRa signals at all.
• Hardware Limitations: The CC2531's RF front-end is optimized for low-power 2.4GHz mesh networks, not long-range LoRa transmissions. There's no way to reconfigure it to handle LoRa's physical layer.

Stick with your RFM9X modules for LoRa sniffing—they're already compatible with the frequencies and modulation you need.

内容的提问来源于stack exchange，提问作者Eng-Mohamad Badr