Tracing TCP Connections on MacOS: Wireshark

I needed to poke an HTTP connection pool and observe connections being reused or reset. On Windows I would reach for SysInternals Process Monitor straight away, but it was suprisingly hard to find solid recommendations for MacOS.

The answer is Wireshark. Case closed. It has way more power than I needed, but it was also super easy to set up and use for exactly what I needed. Install Wireshark, run it, pick a network interface, click Start, click through the recommended driver installation, set a quick filter for the TCP port and SYN flags. Done.