> Can you explain more how you get to 2^48? I thought the protocol specification only reserved two bytes for the port and so getting over 65536 connections would either require using more IP adresses or more ports.

32b IP * 16 bit port?

> You are definitely right that this is not a "full" solution for the c10k problem, but it is an interesting start IMO.

It's not a solution to the C10K at all, because the C10K problem is outdated and was trivialised a decade back. Whatsapp was doing 2 million connections on a single box (with resources to spare) back in 2012: https://blog.whatsapp.com/196/1-million-is-so-2011 and folks were working on C10M: http://highscalability.com/blog/2013/5/13/the-secret-to-10-m...

> Maybe for next month I'll implement basic epoll functionality to make an echo server or something :)

Epoll is bad, why would you want to do that?