ethtool: Linux Command/Unix Command

Display or change your Ethernet card settings

Use the ethtool command in Linux to display or change the settings of your Ethernet device.

Options

The ethtool command alone—with a single argument specifying a device name—prints the current settings of the specified device. The device name is usually rendered as ethX, with X referencing the number of the device. The default Ethernet device is usually rendered as eth0.

ethtool command

Use the man command (% man) to see how a command is used on your computer.

Use the following switches to modify the command's function:

  • -h: Show a short help message.
  • -a: Query the specified Ethernet device for pause parameter information.
  • -A: Change the pause parameters of the specified Ethernet device.
  • autoneg on|off: Specify if pause auto-negotiation is enabled.
  • rx on|off: Specify if RX pause is enabled.
  • tx on|off: Specify if TX pause is enabled.
  • -c: Query the specified Ethernet device for coalescing information.
  • -C: Change the coalescing settings of the specified Ethernet device.
  • -g: Query the specified Ethernet device for rx/tx ring parameter information.
  • -G: Change the rx/tx ring parameters of the specified Ethernet device.
  • rx N: Change the number of ring entries for the Rx ring.
  • rx-mini N: Change the number of ring entries for the Rx Mini ring.
  • rx-jumbo N: Change the number of ring entries for the Rx Jumbo ring.
  • tx N: Change the number of ring entries for the Tx ring.
  • -i: Query the specified Ethernet device for associated driver information.
  • -d: Retrieve and print a register dump for the specified Ethernet device.
  • -e: Retrieve and print an EEPROM dump for the specified Ethernet device.
  • -k: Query the specified Ethernet device for checksumming information.
  • -K: Change the checksumming parameters of the specified Ethernet device.
  • rx on|off: Specify if RX checksumming is enabled.
  • tx on|off: Specify if TX checksumming is enabled.
  • sg on|off: Specify if scatter-gather is enabled.
  • -p: Initiate an adapter-specific action to identify the adapter by sight. This involves blinking one or more LEDs on the specific Ethernet port.
  • N: The length of time to perform phys-id, in seconds.
  • -r: Restart auto-negotiation on the specified Ethernet device, if auto-negotiation is enabled.
  • -S: Query the specified Ethernet device for NIC- and driver-specific statistics.
  • -t: Execute an adapter self-test on the specified Ethernet device. Possible test modes are offline (default) and online. Offline performs a full set of tests and may cause normal operation interruption during the tests. Online performs a limited set of tests, and doesn't interrupt normal adapter operation

Changing Settings

To change the settings for the specified Ethernet device, enter the command ethtool -s with the following switches:

  • speed 10|100|1000: Set the speed in Mb/s. ethtool with a single argument shows the supported device speeds.
  • duplex half|full: Set full-duplex or half-duplex mode.
  • port tp|aui|bnc|mii: Select the device port.
  • autoneg on|off: Specify if auto-negotiation is enabled. In the usual case it is, but might cause problems with some network devices, so you can turn it off.
  • phyad N: The PHY address.
  • xcvr internal|external: Select a transceiver type. Currently only internal and external can be specified, in the future further types might be added.
  • wol p|u|m|b|a|g|s|d...: Set the Wake-on-LAN options. Not all devices support this. The argument to this option is a string of characters specifying which options to enable.
  • p: Wake on phy activity.
  • u: Wake on unicast messages.
  • m: Wake on multicast messages.
  • b: Wake on broadcast messages.
  • a: Wake on ARP.
  • g: Wake on MagicPackettm.
  • s: Enable SecureOntm password for MagicPackettm.
  • d: Disable (wake on nothing). This option clears all previous options.
  • sopass xx:yy:zz:aa:bb:cc: set the SecureOntm password. The argument to this option must be 6 bytes in Ethernet MAC hex format (xx:yy:zz:aa:bb:cc).
  • msglvl N: set the driver message level. Meanings differ per driver.