Less time spent capturing packets

When logs alone do not show the cause of a network failure, you have to look at the packets.

FortiGate (firewall appliance) capture commands required combining source, destination, and port conditions by hand each time, which was slow and error-prone.

I built a Python script by hand that generates the capture command from just the analysis target.

When a capture produced several result files (pcapng, a packet capture file format), Python converted them in one pass instead of one by one.

The time needed to prepare an analysis went down.

In the packets, I check whether the three-step handshake completes, which side sends a connection reset (RST), and whether retransmissions keep repeating.