install newest kernel & bbr:
sudo rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org && sudo rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.el repo.noarch.rpm && sudo yum --enablerepo=elrepo-kernel install kernel-ml -y &&sudo egrep ^menuentry /etc/grub2.cfg | cut -f 2 -d \'
check bbr ranking on boot list:
sudo egrep ^menuentry /etc/grub2.cfg | cut -f 2 -d \'
switch to bbr & reboot:
sudo grub2-set-default <rank>
reboot
bonus: after reboot, check bbr is enabled
sudo sysctl -n net.ipv4.tcp_congestion_control && lsmod | grep bbr
↑ It should show 2 lines with text bbr
on each line