ethtool

Here are a few examples of ethtool use. More examples, man page.

ethtool is being supplanted by nmcli, cli to NetworkManager.

List interfaces

ip link show

Display NIC settings

root@pmox3:~# ethtool enp1s0
Settings for enp1s0:
        Supported ports: [ TP ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
                                2500baseT/Full
        Supported pause frame use: Symmetric Receive-only
        Supports auto-negotiation: Yes
        Supported FEC modes: Not reported
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
                                2500baseT/Full
        Advertised pause frame use: Symmetric Receive-only
        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: Symmetric
        Link partner advertised auto-negotiation: Yes
        Link partner advertised FEC modes: Not reported
        Speed: 1000Mb/s
        Duplex: Full
        Auto-negotiation: on
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        MDI-X: Unknown
        Supports Wake-on: pumbg
        Wake-on: g
        Current message level: 0x00000033 (51)
                               drv probe ifdown ifup
        Link detected: yes

Get MAC address

root@pmox2:~# ethtool -P eno1
Permanent address: 6c:2b:59:f8:0d:f6
root@pmox2:~# ethtool -P vmbr0
Permanent address: not set

Display the driver used

root@pmox2:~# ethtool -i eno1
driver: e1000e
version: 5.15.39-1-pve
firmware-version: 0.5-4
expansion-rom-version:
bus-info: 0000:00:1f.6
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: yes

root@pmox2:~# ethtool -i vmbr0
driver: bridge
version: 2.3
firmware-version: N/A
expansion-rom-version:
bus-info: N/A
supports-statistics: no
supports-test: no
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: no


## Display NIC statistics

Use `ethtool -S enp1s0` or, better yet,  `watch -d "ethtool -S eno1"`.

root@pmox3:~# ethtool -S enp1s0 NIC statistics: tx_packets: 12 rx_packets: 5625 tx_errors: 0 rx_errors: 0 rx_missed: 0 align_errors: 0 tx_single_collisions: 0 tx_multi_collisions: 0 unicast: 0 broadcast: 2206 multicast: 3419 tx_aborted: 0 tx_underrun: 0 tx_octets: 1694 rx_octets: 1310239 rx_multicast64: 0 tx_unicast64: 1 tx_broadcast64: 0 tx_multicast64: 11 tx_pause_on: 0 tx_pause_off: 0 tx_pause_all: 0 tx_deferred: 0 tx_late_collision: 0 tx_all_collision: 0 tx_aborted32: 0 align_errors32: 0 rx_frame_too_long: 0 rx_runt: 0 rx_pause_on: 0 rx_pause_off: 0 rx_pause_all: 0 rx_unknown_opcode: 0 rx_mac_error: 0 tx_underrun32: 0 rx_mac_missed: 0 rx_tcam_dropped: 0 tdu: 0 rdu: 0

## NIC test

root@pmox3:~# ethtool -t eno1 The test result is PASS The test extra info: Register test (offline) 0 Eeprom test (offline) 0 Interrupt test (offline) 0 Loopback test (offline) 0 Link test (on/offline) 0

root@pmox3:~# ethtool -t enp1s0
Cannot test: Operation not supported