Master ethtool: How to Query and Configure Network Interface Settings

ethtool: Query and Set Network Interface Parameters

Function Description

ethtool command is used to query and set network interface parameters.

Command Syntax

ethtool [options] [interface]

Option Meanings

-a Show the status of RX, TX, and Autonegotiation modules: on or off.
-A Modify the status of RX, TX, and Autonegotiation modules: on or off.
-c display the Coalesce information of the specified ethernet card.
-C Change the Coalesce setting of the specified ethernet card.
-g Display the rx/tx ring parameter information of the specified ethernet card.
-G change the rx/tx ring setting of the specified ethernet card.
-i Show driver information such as name and version.
-d Show register dump information; not supported by all drivers.
-e Show EEPROM dump information; not supported by all drivers.
-E Modify EEPROM byte.
-k Show Offload parameters status: on or off, including rx-checksumming, tx-checksumming, etc.
-K Modify Offload parameters status.
-p Identify the physical location of the NIC by flashing its port LED; N indicates duration in seconds.
-r If autonegotiation is on, restarts it.
-S Show NIC- and driver-specific statistics such as bytes and broadcast packets.
-t Run self-test in offline or online mode.
-s Modify interface settings such as speed, duplex mode, MAC address, etc.

Parameter Examples

Example 1: Query Interface Parameters

Query basic information and driver details, and view statistics.

// Query basic interface information
# ethtool ens33

// Identify which physical NIC corresponds to ens33
# ethtool -p ens33 10   // LED flashes for 10 seconds

// Show driver information
# ethtool -i ens33
driver: e1000
version: 7.3.21-k8-NAPI

// Show error statistics
# ethtool -S ens33

Example 2: Configure Interface Parameters

Set work mode, speed, disable TX, and adjust checksum offload.

// Set work mode
# ethtool -s ens33 autoneg off speed 100 duplex full

// Reduce speed to 100Mbps
# ethtool -s ens33 speed 100

// Stop TX module
# ethtool -A tx off ens33

// Verify TX status
# ethtool -a ens33

// Disable receive checksum offload
# ethtool -K ens33 rx off

// Verify checksum offload status
# ethtool -k ens33