Introducing tcpdiff September 21, 2025 on Rustam Kovhaev's blog

Network issues analysis could be very time consuming and complicated.

I’ve seen people struggle at every step along the way to the RCA, especially if they are new to troubleshooting.
I know I’ve had my fair share of struggle when I was young.

I have been working on a small utility that automates network issues analysis for TCP protocol.
For a proper RCA of a network issue you need two capture files, one from source machine and one from target machine.

The utility workflow consists of five parts:

  1. Read two capture files and get all TCP streams
  2. Match TCP streams based on 5-tuple + time
  3. Ask user which TCP stream he would like to analyze
  4. Compare and diff TCP payloads from two files
  5. Analyze termination (TCP FIN/RST) of the TCP stream

RFC PATCH is out on the mailing list:
https://lists.wireshark.org/archives/wireshark-dev/202509/msg00014.html

The same commit on the Gitlab:
https://gitlab.com/rustylife/wireshark/-/commit/57366e7d9e4666f10c8e932ad6e9e668076f009b