How to Enable BBR on CentOS Stream 9

BBR stands for Bottleneck Bandwidth and RTT is a congestion control system. You can enable TCP BBR on your Linux desktop to improve the overall web surfing experience. By default, Linux uses the Reno and CUBIC congestion control algorithm.


  • BBR requires Linux kernel version 4.9 or above. Since CentOS Stream 9 comes with Linux kernel 5.14.0, we can enable BBR right away.

Run the following command to check available congestion control algorithms,

sysctl net.ipv4.tcp_available_congestion_control

Run the below command to check the current congestion control algorithm used in your system,

sysctl net.ipv4.tcp_congestion_control

Enabling TCP BBR in CentOS

Open the following configuration file vi /etc/sysctl.conf to enable TCP BBR.

vi /etc/sysctl.conf

At the end of the config file, add the following lines.


Save the file, and refresh your configuration by using this command,

sysctl -p

Now, Verify if BBR is enabled in your system,

sysctl net.ipv4.tcp_congestion_control

Now you have successfully enabled BBR on CentOS Stream 9.