Learn the sysctl variables into the Linux/Kernel network flow

This is a great summary, thank you. Also attribution for things like (<a href="https:&#x2F;&#x2F;blog.packagecloud.io&#x2F;eng&#x2F;2016&#x2F;10&#x2F;11&#x2F;monitoring-tuning-linux-networking-stack-receiving-data-illustrated&#x2F;" rel="nofollow">https:&#x2F;&#x2F;blog.packagecloud.io&#x2F;eng&#x2F;2016&#x2F;10&#x2F;11&#x2F;monitoring-tunin...</a>) is very much appreciated.