Enable BBR:

echo -e "net.core.default_qdisc=fq\nnet.ipv4.tcp_congestion_control=bbr" >> /etc/sysctl.conf

sysctl -p

Disable IPv6：

echo -e "net.ipv6.conf.all.disable_ipv6=1\nnet.ipv6.conf.default.disable_ipv6=1\nnet.ipv6.conf.lo.disable_ipv6=1" >> /etc/sysctl.conf

sysctl -p