Enabling TCP BBR

Linode Staff

I understand that I can boost network performance by enabling TCP BBR. I currently have Cubic enabled for kernal 5.4.10-x86_64-linode132.

Can you advise on any additional steps required for this Linode instance if I add two lines to /etc/sysctl.conf:

(net.core.default_qdisc=fq and net.ipv4.tcp_congestion_control=bbr)? 

Is there anything else I need to do to make this change?

Thank you for your advise.

2 Replies

As I haven't personally tried to enable BRR, I gave it a shot on Ubuntu 16.04 and was successful with the help of this guide: Easily Boost Ubuntu Network Performance by Enabling TCP BBR.

A successful configuration will yield the below output from sudo sysctl -p:

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

I currently have Cubic enabled for kernal 5.4.10-x86_64-linode132

Based on this you shouldn't need to update your kernel, but if you do follow that step in the guide, it's important to note that you will need to reboot your Linode and make sure the Disk Configuration is booting with Grub2 as the kernel.

Hopefully this helps, but if you have any questions please reach out to us and we'd be happy to help.

Josh E.
Linode Support Team

Thank you @jeochard for testing this. Just to confirm my understanding, I will not need to upgrade the kernel since my version is higher than 4.9 and will only need to add those two lines to sysctl.conf and then reload.


Please enter an answer

You can mention users to notify them: @username

You can use Markdown to format your question. For more examples see the Markdown Cheatsheet.

> I’m a blockquote.

I’m a blockquote.

[I'm a link] (https://www.google.com)

I'm a link

**I am bold** I am bold

*I am italicized* I am italicized

Community Code of Conduct