TCP Selective ACK (SACK)

Since Linux 2.2. (RFC 2018)

sysctl -w net.ipv4.tcp_sack = 1

References

• tcp_sack - tcp(7) - Debian Manpages
• RFC 2018 - TCP Selective Acknowledgment Options
• RFC 7805 - Moving Outdated TCP Extensions and TCP-Related Documents to Historic or Informational Status (2016.4)
• RFC 793 - TRANSMISSION CONTROL PROTOCOL (1981.9)