You must use the Linux kernel version 4.9 or above. On a Debian/Ubuntu Linux type the following grep command/egrep command:
$ grep 'CONFIG_TCP_CONG_BBR' /boot/config-$(uname -r)
$ grep 'CONFIG_NET_SCH_FQ' /boot/config-$(uname -r)
$ egrep 'CONFIG_TCP_CONG_BBR|CONFIG_NET_SCH_FQ' /boot/config-$(uname -r)
Edit the /etc/sysctl.conf file or create a new file in /etc/sysctl.d/ directory:
$ sudo vi /etc/sysctl.conf
OR
$ sudo vi /etc/sysctl.d/10-custom-kernel-bbr.conf
Append the following two lines:
net.core.default_qdisc=fq
net.ipv4.tcp_congestion_control=bbr
$ sudo reboot
OR
$ sudo sysctl --system
You can verify new settings with the following sysctl command. Run:
$ sysctl net.core.default_qdisc
net.core.default_qdisc = fq
$ sysctl net.ipv4.tcp_congestion_control
net.ipv4.tcp_congestion_control = bbr
more info:
https://cloud.google.com/blog/products/gcp/tcp-bbr-congestion-control-comes-to-gcp-your-internet-just-got-faster
