前提
查看当前系统内核版本号，如果是 4.9 及以上版本均已自带 bbr，所以需要先更新内核版本。
[root@demo ~]# uname -r
5.2.10-1.el7.elrepo.x86_64修改系统配置
编辑文件 vim /etc/sysctl.conf ,在文件末尾添加如下内容:
net.core.default_qdisc = fq
net.ipv4.tcp_congestion_control = bbr加载系统参数
确认刚才添加的两条配置项存在
[root@demo ~]# sysctl -p
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
vm.swappiness = 0
net.ipv4.neigh.default.gc_stale_time = 120
net.ipv4.conf.all.rp_filter = 0
net.ipv4.conf.default.rp_filter = 0
net.ipv4.conf.default.arp_announce = 2
net.ipv4.conf.lo.arp_announce = 2
net.ipv4.conf.all.arp_announce = 2
net.ipv4.tcp_max_tw_buckets = 5000
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 1024
net.ipv4.tcp_synack_retries = 2
kernel.sysrq = 1
fs.file-max = 65535
net.core.default_qdisc = fq
net.ipv4.tcp_congestion_control = bbr确认 bbr 已成功开启
[root@demo ~]# sysctl net.ipv4.tcp_available_congestion_control
net.ipv4.tcp_available_congestion_control = reno cubic bbr
[root@demo ~]# sysctl net.ipv4.tcp_congestion_control
net.ipv4.tcp_congestion_control = bbr
[root@demo ~]# lsmod | grep bbr
tcp_bbr 20480 1如上所示，则表示bbr已经成功开启。