ethtool – информация о скорости сетевого интерфейса и ее дуплекс

Если нет – устанавливаем:

$ sudo yum install ethtool

$ sudo ethtool enp5s9
Settings for enp5s9:
    Supported ports: [ TP MII ]
    Supported link modes: 10baseT/Half 10baseT/Full 
                          100baseT/ 100baseT/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 
    Advertised pause frame use: No
    Advertised auto-negotiation: Yes
    Advertised FEC modes: Not reported
    Link partner advertised link modes: 10baseT/Half 10baseT/Full 
                                        100baseT/Half 100baseT/Full 
    Link partner advertised pause frame use: No
    Link partner advertised auto-negotiation: Yes
    Link partner advertised FEC modes: Not reported
    Speed: 100Mb/s
    Duplex: Full
    Port: MII  
    PHYAD: 32
    Transceiver: internal
    Auto-negotiation: on
    Supports Wake-on: pumbg
    Wake-on: d
    Current message level: 0x00000007 (7)
                           drv probe link
    Link detected: yes