Where is your server located?
Physical distance is the #1 cause of latency. Choose a data center close to your players.
Linux kernel tuning:
net.core.rmem_max = 134217728 net.core.wmem_max = 134217728 net.ipv4.tcp_rmem = 4096 87380 67108864 net.ipv4.tcp_wmem = 4096 65536 67108864
Additional tips:
- Disable IPv6 if unused
- Enable BBR congestion control:
sysctl net.ipv4.tcp_congestion_control=bbr
Tip: Measure latency with mtr or pingplotter.