How to Install and Enable Google BBR Acceleration on CentOS, Debian, and Ubuntu

Introduction to Google BBR

Google BBR (Bottleneck Bandwidth and Round-trip propagation time) is an open-source TCP congestion control algorithm developed by Google. It is designed to optimize network transmission performance, especially in high-latency, high-packet-loss network environments. The algorithm has been integrated into the Linux kernel since version 4.9.

System Requirements

• Supported Systems: CentOS 6+, Debian 7+, Ubuntu 12+
• Virtualization: KVM, Xen, VMware, etc. (OpenVZ is NOT supported)
• Memory: ≥ 128MB

One-Click Installation Script

The following script, developed by Teddysun, will automatically install the latest Linux kernel and enable BBR. Execute it in a terminal with root privileges:

wget --no-check-certificate https://github.com/teddysun/across/raw/master/bbr.sh && chmod +x bbr.sh && ./bbr.sh

Note: The script will update the kernel and reboot the system. Ensure you are in an environment where a reboot is acceptable.

Verifying the Installation

After the system reboots, follow these steps to verify BBR is enabled.

1. Check Kernel Version

First, confirm the kernel has been upgraded to a version that supports BBR (typically 4.9 or higher).

uname -r

2. Check Available Congestion Control Algorithms

Run the following command. The output should include bbr.

sysctl net.ipv4.tcp_available_congestion_control

Expected output example:

net.ipv4.tcp_available_congestion_control = bbr cubic reno

3. Check Current Congestion Control Algorithm

Confirm that the default algorithm is bbr.

sysctl net.ipv4.tcp_congestion_control

Expected output example:

net.ipv4.tcp_congestion_control = bbr

4. Check Queue Discipline

Check if the default queue discipline is fq.

sysctl net.core.default_qdisc

Expected output example:

net.core.default_qdisc = fq

5. Check BBR Kernel Module

Check if the tcp_bbr module is loaded.

lsmod | grep bbr

The expected output should include tcp_bbr. Note: This module may not be visible in all environments. If the previous steps succeeded, BBR is usually working even if this command shows no output.

Troubleshooting and Notes

• Script Source: This script is from the open-source community. Ensure you trust the source before using it. For production environments, testing in a small-scale environment first is recommended.
• Kernel Compatibility: If your system already uses a newer kernel (e.g., 5.x), BBR may be enabled by default, making this script unnecessary.
• Network Environment: The effectiveness of BBR varies depending on the network conditions. Improvements may not be significant in some scenarios.
• Manual Configuration: Advanced users can manually enable BBR by editing the /etc/sysctl.conf file, but using the script is more convenient.