config meaning
/proc/sys/net/ipv4/tcp_abort_on_overflow 1: send RST if accept queue is full default 0
/proc/sys/net/ipv4/tcp_synack_retries number of tcp reties
/proc/sys/net/ipv4/tcp_max_syn_backlog max length of the queue contains all incomplete socket system wide

greate resources:

  • tcp-backlog : http://veithen.io/2014/01/01/how-tcp-backlog-works-in-linux.html but in fact, linux does not send sync/ack back. see my post on tcp-backlog
  • linux ip configs : https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt