Agreed. There are a lot of other possible optimizations, from the often-mentioned buffer size settings: net.core.rmem_max / net.core.wmem_max net.ipv4.tcp_

Agreed. There are a lot of other possible optimizations, from the often-mentioned buffer size settings: net.core.rmem_max / net.core.wmem_max net.ipv4.tcp_rmem / net.ipv4.tcp_wmem to metric tunings like: net.ipv4.tcp_no_metrics_save / net.ipv4.tcp_moderate_rcvbuf I've been playing around with these settings on very loaded machines: # Retry SYN/ACK only three times, instead of five net.ipv4.tcp_synack_retries = 3 # Try to close things only twice net.ipv4.tcp_orphan_retries = 2 # FIN-WAIT-2 for only 5 seconds net.ipv4.tcp_fin_timeout = 5 # Increase syn socket queue size (default: 512) net.ipv4.tcp_max_syn_backlog = 2048 # One hour keepalive with fewer probes (default: 7200 & 9) net.ipv4.tcp_keepalive_time = 3600 net.ipv4.tcp_keepalive_probes = 5 # Max packets the input can queue net.core.netdev_max_backlog = 2500 # Keep fragments for 15 sec (default: 30) net.ipv4.ipfrag_time = 15 # Use H-TCP congestion control net.ipv4.tcp_congestion_control = htcp