Ethtool

Ethtool: Linux Utility for Network Interface Configuration

Ethtool is a Linux utility that allows users to query information and configure network interface controllers. It can show and change settings like speed, duplex mode, auto-negotiation, wake-on-LAN, and more.

What is Ethtool?

Ethtool is a utility software included in Linux distributions that allows users to query information and configure network interface controllers. It provides a command line interface to view and change settings on network interfaces.

Some of the key features and information Ethtool can show and configure include:

• Speed and duplex settings like 10Mbps half duplex or 100Mbps full duplex
• Auto-negotiation status and control
• Wake-on-LAN settings
• PCI, MAC, PHY, and driver details
• Statistics like packet counters, errors, and collision counts
• Offload features like checksumming and TCP segmentation
• Diagnostics like cable tests and network loopback

Ethtool is useful for debugging network issues, forcing interface speeds, determining driver and hardware details, measuring interface usage, and testing cables and ports. It provides low-level access that NetworkManager and ifconfig don't offer on their own.

It's included by default in Linux distros like Ubuntu, Fedora, CentOS, Debian, etc, so no additional downloads or installations are necessary. Common use cases are to force 1Gbps speeds if auto-negotiation fails, check error counters to identify hardware issues, or diagnose poor cable connections.

Ethtool Features

Official Links