1#!/bin/bash 2# SPDX-License-Identifier: GPL-2.0 3# 4# Set standard production config values that relate to TCP behavior. 5 6# Flush old cached data (fastopen cookies). 7ip tcp_metrics flush all > /dev/null 2>&1 8 9# TCP min, default, and max receive and send buffer sizes. 10sysctl -q net.ipv4.tcp_rmem="4096 540000 $((15*1024*1024))" 11sysctl -q net.ipv4.tcp_wmem="4096 $((256*1024)) 4194304" 12 13# TCP timestamps. 14sysctl -q net.ipv4.tcp_timestamps=1 15 16# TCP SYN(ACK) retry thresholds 17sysctl -q net.ipv4.tcp_syn_retries=5 18sysctl -q net.ipv4.tcp_synack_retries=5 19 20# TCP Forward RTO-Recovery, RFC 5682. 21sysctl -q net.ipv4.tcp_frto=2 22 23# TCP Selective Acknowledgements (SACK) 24sysctl -q net.ipv4.tcp_sack=1 25 26# TCP Duplicate Selective Acknowledgements (DSACK) 27sysctl -q net.ipv4.tcp_dsack=1 28 29# TCP FACK (Forward Acknowldgement) 30sysctl -q net.ipv4.tcp_fack=0 31 32# TCP reordering degree ("dupthresh" threshold for entering Fast Recovery). 33sysctl -q net.ipv4.tcp_reordering=3 34 35# TCP congestion control. 36sysctl -q net.ipv4.tcp_congestion_control=cubic 37 38# TCP slow start after idle. 39sysctl -q net.ipv4.tcp_slow_start_after_idle=0 40 41# TCP RACK and TLP. 42sysctl -q net.ipv4.tcp_early_retrans=4 net.ipv4.tcp_recovery=1 43 44# TCP method for deciding when to defer sending to accumulate big TSO packets. 45sysctl -q net.ipv4.tcp_tso_win_divisor=3 46 47# TCP Explicit Congestion Notification (ECN) 48sysctl -q net.ipv4.tcp_ecn=0 49 50sysctl -q net.ipv4.tcp_pacing_ss_ratio=200 51sysctl -q net.ipv4.tcp_pacing_ca_ratio=120 52sysctl -q net.ipv4.tcp_notsent_lowat=4294967295 > /dev/null 2>&1 53 54sysctl -q net.ipv4.tcp_fastopen=0x70403 55sysctl -q net.ipv4.tcp_fastopen_key=a1a1a1a1-b2b2b2b2-c3c3c3c3-d4d4d4d4 56 57sysctl -q net.ipv4.tcp_syncookies=1 58 59# Override the default qdisc on the tun device. 60# Many tests fail with timing errors if the default 61# is FQ and that paces their flows. 62tc qdisc add dev tun0 root pfifo 63 64