In this tip we will see how to use the terminal to check and change the current speed of your network card under Ubuntu or any Debian-based system. This tip will be useful for those having incorrect network card speed that is running for example at 100Mb/s rather than 1000Mb/s.
To check the current network card speed, we will use the "ethtool" command line utility. To install it under Ubuntu/Debian, run the following command:
sudo apt-get install ethtool
Replace "eth0" with your own network interface (eth1, eth2, etc.). Here are the outputs returned for my system (speed is displayed under the "Advertised auto-negotiation (...) line):
~$ sudo ethtool eth0 Settings for eth0: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 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: umbg Wake-on: d Current message level: 0x00000007 (7) drv probe link Link detected: yes
To change for example the speed of your network card from 100Mb/s to 1000M/s, run this command:
sudo ethtool -s eth0 speed 1000 duplex full autoneg off