ethtool – Ethernet Device Configuration Tool

ethtool is a standard Linux utility for querying and modifying network interface card (NIC) settings. It provides detailed information about Ethernet devices including driver information, link status, speed negotiation, and hardware offloading capabilities. System administrators use ethtool to diagnose network issues, optimize performance, and configure advanced NIC features.

Key Features

• Link Status – Check connection state and negotiate speed/duplex
• Driver Information – View driver version and firmware details
• Statistics – Access detailed NIC counters and error statistics
• Offload Settings – Configure TCP/UDP checksum and segmentation offloading
• Wake-on-LAN – Enable and configure WoL capabilities
• Ring Buffers – Adjust RX/TX ring buffer sizes for performance

Installation

# Debian/Ubuntu
sudo apt install ethtool

# RHEL/CentOS/Fedora
sudo dnf install ethtool

# Arch Linux
sudo pacman -S ethtool

Common Usage Examples

# Show interface settings
sudo ethtool eth0

# Check link status
sudo ethtool eth0 | grep "Link detected"

# View driver information
sudo ethtool -i eth0

# Show NIC statistics
sudo ethtool -S eth0

# Set speed and duplex
sudo ethtool -s eth0 speed 1000 duplex full autoneg off

# Enable Wake-on-LAN
sudo ethtool -s eth0 wol g

# Show offload settings
sudo ethtool -k eth0

Use Cases

ethtool is crucial for troubleshooting network connectivity, optimizing NIC performance, diagnosing hardware issues, configuring Wake-on-LAN, and fine-tuning network settings in high-performance environments.

Download ethtool