debian13 enable bbr

Question

debian13 enable bbr

Accepted Answer

To enable BBR (Bottleneck Bandwidth and Round-trip propagation time) on Debian 13, follow these steps to load the kernel module and configure the system settings.

### 1. Load the BBR Kernel Module
First, ensure the `tcp_bbr` module is loaded into the kernel.
```bash
sudo modprobe tcp_bbr
```
Verify that the module is loaded:
```bash
lsmod | grep bbr
```
If successful, you should see `tcp_bbr` in the output. To make this permanent across reboots, add it to your modules configuration:
```bash
echo "tcp_bbr" | sudo tee /etc/modules-load.d/bbr.conf
```

### 2. Configure Sysctl Settings
You need to set the congestion control algorithm to `bbr` and the queuing discipline to `fq`. It is recommended to create a dedicated configuration file:

1. Create/edit the configuration file:
   ```bash
   sudo nano /etc/sysctl.d/99-bbr.conf
   ```
2. Add the following lines to the file:
   ```text
   net.core.default_qdisc = fq
   net.ipv4.tcp_congestion_control = bbr
   ```
3. Save and close the file (in nano, press `Ctrl+O`, `Enter`, then `Ctrl+X`).

### 3. Apply and Verify
Apply the changes without rebooting:
```bash
sudo sysctl -p /etc/sysctl.d/99-bbr.conf
```

Finally, verify that BBR is active:
```bash
sysctl net.ipv4.tcp_congestion_control
```
The output should return:
`net.ipv4.tcp_congestion_control = bbr`