Ubuntu Linux Display List of Ethernet Adapter

How do I display a list of all installed Ethernet adapters on Ubuntu Linux?

You can use the following commands to list Ethernet adapters under Ubuntu Linux. Open a command-line terminal (select Applications > Accessories > Terminal), and then type:
$ lspci
$ lspci | less
$ lspci | grep -i eth
Sample outputs:

09:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5761e Gigabit Ethernet PCIe (rev 10)

Above output indicates that my system has one Gigabit Ethernet controller installed using PCIe interface. It also displayed named of the manufacture. To list actual ip address assigned to the interface, enter:
$ ifconfig
$ ifconfig eth0
Sample outputs:

eth0      Link encap:Ethernet  HWaddr b8:ac:6f:65:31:e5
          inet addr:192.168.2.11  Bcast:192.168.2.255  Mask:255.255.255.0
          inet6 addr: fe80::baac:6fff:fe65:31e5/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1938092 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2436052 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:771061372 (771.0 MB)  TX bytes:2118333235 (2.1 GB)
          Interrupt:17

Display or Change Ethernet Card Settings

You can use the ethtool command for querying settings of an ethernet device and changing them such as speed, duplex settings and much more:
$ ethtool eth0
Sample outputs:

Settings for eth0:
 Supported ports: [ TP ]
 Supported link modes:   10baseT/Half 10baseT/Full
                         100baseT/Half 100baseT/Full
                         1000baseT/Half 1000baseT/Full
 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
 Link partner advertised link modes:  Not reported
 Link partner advertised pause frame use: No
 Link partner advertised auto-negotiation: No
 Speed: 100Mb/s
 Duplex: Full
 Port: Twisted Pair
 PHYAD: 1
 Transceiver: internal
 Auto-negotiation: on
 MDI-X: Unknown
 Supports Wake-on: g
 Wake-on: g
 Current message level: 0x000000ff (255)
 Link detected: yes

See how to change duplex settings with the ethtool command under Linux operating systems.