SSH

vim /etc/ssh/sshd_config

修改如下：

PubkeyAuthentication yes
AuthorizedKeysFile  .ssh/authorized_keys
PermitRootLogin no
PasswordAuthentication no

BBR

sed -i '/net.core.default_qdisc/d' /etc/sysctl.conf
sed -i '/net.ipv4.tcp_congestion_control/d' /etc/sysctl.conf
echo "net.core.default_qdisc = fq" >> /etc/sysctl.conf
echo "net.ipv4.tcp_congestion_control = bbr" >> /etc/sysctl.conf
sysctl -p

# 查看成效
sysctl net.ipv4.tcp_available_congestion_control
lsmod | grep bbr