5-2.CentOS8打开BBR加速，使用阿里云轻量的设置

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CentOS8打开BBR加速，使用阿里云轻量的设置
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打开BBR
vi /etc/sysctl.conf

将内容修改为

vm.swappiness = 0
kernel.sysrq=1

net.ipv4.neigh.default.gc_stale_time=120

# see details in https://help.aliyun.com/knowledge_detail/39428.html
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

# see details in https://help.aliyun.com/knowledge_detail/41334.html
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

net.core.default_qdisc = fq
net.ipv4.tcp_congestion_control = bbr

保存离开
:wq

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关闭selinux
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vi  /etc/sysconfig/selinux

改為
SELINUX=disabled

保存离开
:wq

重启 
sudo reboot

sysctl net.ipv4.tcp_available_congestion_control

返回值一般为：
net.ipv4.tcp_available_congestion_control = reno cubic bbr

sysctl net.ipv4.tcp_congestion_control

返回值一般为：
net.ipv4.tcp_congestion_control = bbr

sysctl net.core.default_qdisc

返回值一般为：
net.core.default_qdisc = fq

lsmod | grep bbr

返回值有 tcp_bbr

说明 bbr 已启动