Debian 9 enables Google BBR to achieve TCP acceleration

Since the default 4.9 kernel of Debian9 has compiled TCP BBR content, it can be enabled directly through parameters.

The following operations are all performed under SSH, preferably as the root user.
1. Modify system variables

 echo "net.core.default_qdisc=fq" >> /etc/sysctl.conf echo "net.ipv4.tcp_congestion_control=bbr" >> /etc/sysctl.conf

2. Save and take effect

 sysctl -p

3. Check whether BBR is enabled in the kernel

 sysctl net.ipv4.tcp_available_congestion_control

The following content is displayed to indicate that it is enabled:

 sysctl net.ipv4.tcp_available_congestion_control net.ipv4.tcp_available_congestion_control = bbr cubic reno

4. BBR should have been started through the above operations. Then check whether BBR is started.

 lsmod | grep bbr

The following is displayed, indicating successful startup:

 lsmod | grep bbr tcp_bbr 20480 14