Ethtool

ethtool command is used to view and modify network device drivers setting, in particular wired Ethernet devices.

Examples

ethtool eno1
Settings for eno1:
	Supported ports: [ TP ]
	Supported link modes:   10baseT/Half 10baseT/Full
	                        100baseT/Half 100baseT/Full
	                        1000baseT/Half 1000baseT/Full
	Supported pause frame use: No
	Supports auto-negotiation: Yes
	Supported FEC modes: Not reported
	Advertised link modes:  10baseT/Half 10baseT/Full
	                        100baseT/Half 100baseT/Full
	                        1000baseT/Half 1000baseT/Full
	Advertised pause frame use: Symmetric
	Advertised auto-negotiation: Yes
	Advertised FEC modes: Not reported
	Link partner advertised link modes:  10baseT/Half 10baseT/Full
	                                     100baseT/Half 100baseT/Full
	                                     1000baseT/Full
	Link partner advertised pause frame use: No
	Link partner advertised auto-negotiation: Yes
	Link partner advertised FEC modes: Not reported
	Speed: 1000Mb/s
	Duplex: Full
	Port: Twisted Pair
	PHYAD: 4
	Transceiver: internal
	Auto-negotiation: on
	MDI-X: off
	Supports Wake-on: g
	Wake-on: g
	Current message level: 0x000000ff (255)
			       drv probe link timer ifdown ifup rx_err tx_err

ethtool ens3f1
Settings for ens3f1:
	Supported ports: [ ]
	Supported link modes:   1000baseT/Full
	                        1000baseKX/Full
	                        10000baseT/Full
	                        1000baseX/Full
	                        10000baseSR/Full
	                        10000baseLR/Full
	Supported pause frame use: Symmetric
	Supports auto-negotiation: Yes
	Supported FEC modes: Not reported
	Advertised link modes:  1000baseT/Full
	                        1000baseKX/Full
	                        10000baseT/Full
	                        1000baseX/Full
	                        10000baseSR/Full
	                        10000baseLR/Full
	Advertised pause frame use: No
	Advertised auto-negotiation: Yes
	Advertised FEC modes: Not reported
	Speed: Unknown!
	Duplex: Unknown! (255)
	Port: Other
	PHYAD: 0
	Transceiver: internal
	Auto-negotiation: off
	Supports Wake-on: d
	Wake-on: d
	Current message level: 0x00000007 (7)
			       drv probe link
	Link detected: no

See also

• ifconfig, ethtool or obsolete mii-tool (mii-tool -v eth0) nmcli device show, eth0, Network manager
• Ethernet: MII, MDI, bonding, etherchannel, STP, ARP, MAC, STP, Jumbo frames, 802.1X, MTU, Ethernet In-Band Access (IBA), LACP, Multicast, Broadcast, SPI

http://man7.org/linux/man-pages/man8/ethtool.8.html