Sockets in a Bind: Troubleshooting Port Exhaustion in Heroku's Routing Layer (engineering.heroku.com)

The linked article does a much better job of explaining the problem. Just read this one: https://idea.popcount.org/2014-04-03-bind-before-connect/

A better solution would be relatively new socket option:

IP_BIND_ADDRESS_NO_PORT

https://www.mail-archive.com/netdev@vger.kernel.org/msg66879...

That C code has a buffer overflow. Also they call atoi unnecessarily in each loop iteration.

This type of thing would not have been an issue 15 years ago. This is Richard Stevens socket programming 101.