Full duplex or Half duplex?

andy18    Linux-related    

In Linux environment, you may check if your NIC is running in full/half duplex by executing the following command:

root@localhost [~]# ethtool eth0

Output of the result as:

Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Advertised auto-negotiation: Yes
Speed: 100Mb/s
Duplex: Full
Port: MII
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: g
Wake-on: g
Current message level: 0×00000007 (7)
Link detected: yes

root@localhost [~]# dmesg | grep -i duplex

Output of the result as:

e100: eth0: e100_watchdog: link up, 100Mbps, full-duplex
e100: eth0: e100_watchdog: link up, 100Mbps, full-duplex
e100: eth0: e100_watchdog: link up, 100Mbps, full-duplex
e100: eth0: e100_watchdog: link up, 100Mbps, full-duplex

e100: eth0: e100_watchdog: link up, 100Mbps, full-duplex

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