ethtool is a utility for Linux kernel-based operating system for displaying and modifying some parameters of network interface controllers (NICs) and their device drivers. ethtool is developed parallel to the Linux kernel.
Examples os uses:
ethtool -s eth0 speed 10 duplex half autoneg offethtool -s eth0 speed 100 duplex full autoneg offGet speed and other information for eth0:
# ethtool eth0Settings 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: yesInteresting link: http://en.wikipedia.org/wiki/Ethtool