1.Use ethtool command
[root@test ~]# ethtool eth0 Settings for eth0: 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 Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Half 1000baseT/Full Advertised pause frame use: No Advertised auto-negotiation: Yes Speed: 100Mb/s Duplex: Full Port: Twisted Pair PHYAD: 0 Transceiver: internal Auto-negotiation: on MDI-X: Unknown Supports Wake-on: pg Wake-on: d Current message level: 0x000000ff (255) drv probe link timer ifdown ifup rx_err tx_err Link detected: yes [root@test ~]#
2.use dmesg | grep -i duplex command
[root@test~]# dmesg | grep -i duplex sky2 eth0: Link is up at 100 Mbps, full duplex, flow control rx [root@test~]#
