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networkingtcpnetwork-protocolswiresharkwireshark-dissector

TFO Option number?

I am to write a dissector for TFO in wireshark and was wondering what was the option number for this? I am not able to find this anywhere online

https://datatracker.ietf.org/doc/html/draft-cheng-tcpm-fastopen-02

Regards,

Vinay Pai B.H.

Solution

  • It's not standardized yet. In Linux it is using TCPOPT_EXP which is 254, followed by TCPOPT_FASTOPEN_MAGIC which is 0xF989.

    This adheres to RFC 6994 which outlines a scheme for experimental options.