Network Card (NIC)

A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter or physical network interface, and by similar terms) is a computer hardware component that connects a computer to a computer network.

Set RX/TX on boot before

Check current RX TX values

ethtool -g enp0s31f6

The output

The output of this command should look like this:

Ring parameters for enp0s31f6:
Pre-set maximums:
RX:             4096
RX Mini:        0
RX Jumbo:       0
TX:             4096
Current hardware settings:
RX:             256
RX Mini:        0
RX Jumbo:       0
TX:             256

As you can se we shold set much higher values.

Create ethtool script

nano /usr/bin/

Add these lines to

ethtool -G enp0s31f6 rx 4096 tx 4096
echo "RX TX has been set to 4096"

Create the startup script

You can use ifup.pre or other ways to run the script, but with systemd-networkd you should follow the next steps.

nano /lib/systemd/system/network-rx-tx.service

Add these lines to network-rx-tx.service

Description=NetworkRXTX Setter 




Enable the service

systemctl enable network-rx-tx.service

Fix high SoftIRQ on 4.13 kernel

Create /etc/sysctl.d/99-network-tuning.conf file

touch /etc/sysctl.d/99-network-tuning.conf

Insert the following text into /etc/sysctl.d/99-network-tuning.conf

The code below also contains various buffer updates.

# Increase Linux autotuning TCP buffer limits
# Set max to 16MB for 1GE and 32M (33554432) or 54M (56623104) for 10GE
# Don't set tcp_mem itself! Let the kernel scale it based on RAM.
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.core.rmem_default = 16777216
net.core.wmem_default = 16777216
net.core.optmem_max = 40960 

# cloudflare uses this for balancing latency and throughput
net.ipv4.tcp_rmem = 4096 1048576 2097152 

net.ipv4.tcp_wmem = 4096 65536 16777216

# Also increase the max packet backlog
net.core.netdev_max_backlog = 100000
net.core.netdev_budget = 50000

# Make room for more TIME_WAIT sockets due to more clients,
# and allow them to be reused if we run out of sockets
net.ipv4.tcp_max_syn_backlog = 30000
net.ipv4.tcp_max_tw_buckets = 2000000
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_fin_timeout = 10

# Disable TCP slow start on idle connections
net.ipv4.tcp_slow_start_after_idle = 0

# If your servers talk UDP, also up these limits
net.ipv4.udp_rmem_min = 8192
net.ipv4.udp_wmem_min = 8192

# Actual fix for high softirq in 4.13
net.core.netdev_budget_usecs = 5000

Reboot the server