Abusing Linux's firewall: the hack that allowed us to build Spectrum
https://blog.cloudflare.com/how-we-built-spectrum/ [blog.cloudflare.com]
2018-04-30 01:39
Soon after we started building Spectrum, we hit a major technical obstacle: Spectrum requires us to accept connections on any valid TCP port, from 1 to 65535. On our Linux edge servers it’s impossible to “accept inbound connections on any port number”. This is not a Linux-specific limitation: it’s a characteristic of the BSD sockets API, the basis for network applications on most operating systems.