ethtool

Show settings

$ ethtool eth0

$ ethtool -i eth0

$ ethtool -k eth0

$ ethtool -S eth0

$ ethtool -p eth0 10

$ ethtool -s eth0 speed 1000 duplex full autoneg off

ethtool [OPTIONS] device

ethtool displays and modifies Network Interface Controller (NIC) parameters. It provides comprehensive control over Ethernet device settings, allowing administrators to query driver information, link status, hardware capabilities, and configure parameters like speed, duplex mode, and various offload features.
The tool is essential for network troubleshooting, performance tuning, and hardware diagnostics. It can enable or disable features like checksumming offload, scatter-gather I/O, and segmentation offloading that affect network throughput and CPU utilization.
ethtool works directly with network device drivers, exposing hardware-specific capabilities and statistics not available through standard networking tools.

-i, --driver

Display driver information

Show offload and other features

Change offload and other features

Show NIC and driver statistics

Blink device LEDs for identification

Change device settings

Set link speed in Mbps

Set duplex mode

Enable/disable auto-negotiation

Not all options are supported by all drivers. Changing settings may temporarily disrupt connectivity. Some settings require the interface to be down.

ethtool is the standard Linux utility for examining and tuning Ethernet-based network interfaces.

ip(8), mii-tool(8), tc(8)