TCP Tuning for iperf3

(2024-06-03)

Found this set of recommendations for TCP tuning while chasing some iperf3 issues revolving around windowing problems.

I created this as /etc/sysctl.d/20-network-tcp-tuning:

# https://blog.cloudflare.com/optimizing-tcp-for-high-throughput-and-low-latency/
net.ipv4.tcp_rmem = 8192 262144 536870912
net.ipv4.tcp_wmem = 4096 16384 536870912
net.ipv4.tcp_adv_win_scale = -2
net.ipv4.tcp_collapse_max_bytes = 6291456
net.ipv4.tcp_notsent_lowat = 131072