Realtek PCIe GBE NIC Driver

Applicable for RTL8111/8168/8411 PCIe GBE NIC.

Using the official driver will resolve sending rate being capped at 4MB/s per tcp connection under tcp-bbr, typically when you're using the default r8169 nic driver on RTL8168 device. Newer distros like Ubuntu 18.04.3 with a mainline Linux 5.3 should not have the problem any more. You should try this driver only if you did notice the sending rate degradation.

Install dependences (assume sudo su)
```
apt update && apt install build-essential libelf-dev linux-headers-$(uname -r)
```
Note: Download header packages by yourself if you are using Ubuntu PPA kernel.
Download and install the driver (assume sudo su)

This repo contains a copy of the official driver (8.047.05, tested working as of Linux 5.3):
```
git clone https://github.com/airium/Realtek-PCIe-GBE-NIC-Driver.git
cd Realtek-PCIe-GBE-NIC-Driver/r8168-8.047.05
sh autorun.sh
# this script will break the network temporarily
# on Ubuntu 16/18, your ssh session will be automatically resumed in ~1 minute
# on Debian 8/9, you might have to reboot manually after ~5 minutes
```
Note: You can also check newer drivers from Realtek's official site. You probably have to search for new ones if Realtek once again changed their url). mtorromeo seems to be very happy to do a long-term mirroring.

Check if the driver of the network interface in which you are interested has been updated (assume sudo su)

for i in $(ls /sys/class/net); do
    echo $i '====================='
    ethtool -i $i
done

Example of success

enp4s0 =====================
driver: r8168
version: 8.047.05-NAPI
firmware-version:
expansion-rom-version:
bus-info: 0000:04:00.0
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: yes
supports-priv-flags: no

Note: You need to re-install the driver after changing kernel.

Reference

https://www.unixblogger.com/how-to-get-your-realtek-rtl8111rtl8168-working-updated-guide/

Compared with the reference, this guide complements necessary dependencies, and removes the blacklist operation (it seems the Realtek driver will do it for you).

airium/Realtek-PCIe-GBE-NIC-Driver

Realtek PCIe GBE NIC Driver

Reference