VPN

Linux VPN server

sysctl net.ipv4.ip_forward=1

iptables -t nat -A POSTROUTING -s 192.168.0.0/16 -j MASQUERADE
iptables -t nat -A POSTROUTING -s 10.0.0.0/8 -j MASQUERADE
iptables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu

/etc/sysctl.conf

net.ipv4.ip_forward=1
net.ipv4.tcp_congestion_control=bbr
net.core.default_qdisc=fq

Run sysctl -p to take effect.