Make your childhood dream come true, remote control the IoT train from any device! You need the following to complete the Matter IoTrain “track”:

  1. Factory reset “the train” + put into commission mode.
  2. Find the secret onboarding information.

Please do not touch the train, the tracks, or the microcontroller. They are literally held together by duct tape.

How do I factory reset the device + put it into commission mode?#

This page will list questions—see below. Write down the answers, concatenating the first letters of the answers. Make it lowercase. Use it like https://hackmatter4.fun/posts/ ab12cd23ef to view the solution page.

The information needed to answer these questions is available on the Internet. Feel free to Bing/Duckduckgo/Google/Gemini/ChatGPT/Claude/Deepseek to get the answers. Fun fact: some LLMs are known to give incorrect answers for some of the questions ¯\(ツ)/¯. Sorry, not sorry.

You can be sure that the IoTrain is in factory reset/commission mode if the LED on the train is blinking.

How do I find the onboarding information?#

There are multiple ways Matter devices can be onboarded: QR codes, manual pairing codes, setup PIN codes, etc. Could you find the missing piece by looking around?

What do I get for finishing the Matter train track?#

  1. You can take a selfie with the working train! Use #MatterLED

  2. Optionally recognition on the assistant’s Bluesky/LinkedIn feed (optionally with a selfie with me + optionally a hug) :)

  3. Grab one LED, ask the assistant (red, white, green, blue, yellow are the available colors).

The questions#

  1. Which TCP port is used by Matter by default?
  2. In this network, while the LED Matter device advertises itself via Matter mDNS response type TXT, what is the value of the DN (device name) record? Tip: It is easier to solve this from a generic computer compared to a smartphone, but if you only have a smartphone, you just have to figure out how DN maps to commissioned device attributes. Or ask the assistant for the pcap and use an online pcap parser (e.g. lab.dynamite.ai).
  3. If a device advertises VP=5540+1 during Matter commissioning, what is the vendor name for the device?
  4. What are the three main connection types/transport technologies by which Matter devices are connected to the network? Ethernet, Wi-Fi, and ….?
  5. Which acronym/technology is not related to Matter? CASE, PASE, DAC, X.509, NOC, DCL, X.25, IPv6
  6. What is the underlying technology for “Distributed Compliance Ledger”?
  7. Which encryption standard is used for encrypting messages between Matter devices?
  8. Is cloud/Internet connectivity needed for local Matter commission/control of the devices?
  9. If a Matter device is in a factory reset and commission mode, and the device is not connected (or does not support) Ethernet, what technology is used for initial communication with the device?
  10. Solve the thread_chall , what is the first letter of the vendor?

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