Unable to Decode Matter IM Traffic in Wireshark using nRF52840-DK as Thread Sniffer

asked 2025-12-17 07:27:53 +0000

updated 2025-12-17 12:25:05 +0000

Chuckc gravatar image

I have developed a Matter-over-Thread light bulb using the Silicon Labs EFR32MG24 platform, with CHIP_CONFIG_SECURITY_TEST_MODE = 1 enabled. In parallel, I have set up an OpenThread Border Router (OTBR) on a Raspberry Pi and retrieved the Thread network key.
I also built the Matter Wireshark dissector (version 3.6.25) and am using an nRF52840-DK as a Thread sniffer. While I have successfully configured Wireshark for Thread packet decoding and reviewed the reference Matter captures, I am still unable to observe any Interaction Model (IM) traffic in Wireshark. This includes, but is not limited to:

•   Command requests and responses
•   Attribute read and write operations
•   Subscriptions
•   Events
•   Cluster-level communication
•   User Directed Commissioning (UDC)
•   On/Off cluster interactions

Despite verifying the Thread configuration and keys, the IM messages are not being decoded or displayed. For additional context, both the OTBR and chip-tool are built and running in security test mode. I enabled the CHIP_CONFIG_SECURITY_TEST_MODE = 1 flag and built chip-tool using the following command, as specified in config/python/CHIPProjectConfig.h:

gn gen out/debug --args='treat_warnings_as_errors=false'

I would appreciate your guidance on the correct procedure to capture and decode Matter Interaction Model messages in Wireshark.

if any config images required pls feel free to ping me [email protected]

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Comments

Is this the test plan you're using: Using Wireshark to Capture Network Traffic in Matter

Do the test captures (matter-dissector /tests) decode properly?

Chuckc gravatar imageChuckc ( 2025-12-17 12:36:16 +0000 )edit

Since 4.2.0, Wireshark has included a built in Matter dissector. Is there a reason you need to use a third party dissector and apparently an older, out of support version of Wireshark?

johnthacker gravatar imagejohnthacker ( 2025-12-17 18:40:16 +0000 )edit