Centos 7 开启BBR

# 升级内核
rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm

yum --enablerepo=elrepo-kernel install kernel-ml -y

# 查看当前启动顺序
egrep ^menuentry /etc/grub2.cfg | cut -f 2 -d \'

CentOS Linux (4.20.4-1.el7.elrepo.x86_64) 7 (Core)
CentOS Linux 7 Rescue 52576f5b3c2e410baf87b3c1f4bc78fb (3.10.0-957.1.3.el7.x86_64)
CentOS Linux (3.10.0-957.1.3.el7.x86_64) 7 (Core)
CentOS Linux (3.10.0-693.11.6.el7.x86_64) 7 (Core)
CentOS Linux (3.10.0-693.el7.x86_64) 7 (Core)
CentOS Linux (0-rescue-00a62363617944e08db8db894ba6145e) 7 (Core)

# 设置更新后的内核为默认启动
grub2-set-default 0   #（CentOS Linux (4.20.4-1.el7.elrepo.x86_64) 7 (Core)）

# 重启
reboot

# 开启bbr
echo 'net.core.default_qdisc=fq' | sudo tee -a /etc/sysctl.conf
echo 'net.ipv4.tcp_congestion_control=bbr' | sudo tee -a /etc/sysctl.conf
sysctl -p

# 查看是否已经加载bbr模块
lsmod | grep bbr