Linux change the speed and duplex settings

REF: https://www.cyberciti.biz/faq/linux-change-the-speed-and-duplex-settings-of-an-ethernet-card/

Task: Get speed and other information for eth0

Type following command as root user:
# ethtool eth0Output:

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: 32
     Transceiver: internal
     Auto-negotiation: on
     Supports Wake-on: pumbg
     Wake-on: d
     Current message level: 0x00000007 (7)
     Link detected: yes

Or use mii-tool command as follows:# mii-tool eth0Output:

eth0: negotiated 100baseTx-FD flow-control, link ok