1, display the routing table
$netstat -r
$route –n
$ip route show
$ ip addr show
2, display interface
$netstat -i
ifconfig for detailed interface information, root previledge might be needed
3, display connections
$netstat -ta
4. display listening server sockets
$netstat -l

ethtool example:

# sudo ethtool eth0
Settings for eth0:
Supported ports: [ TP ]
Supported link modes: 1000baseT/Full
Supported pause frame use: No
Supports auto-negotiation: No
Advertised link modes: Not reported
Advertised pause frame use: No
Advertised auto-negotiation: No
Speed: 10000Mb/s
Duplex: Full
Port: Twisted Pair
Transceiver: internal
Auto-negotiation: off
MDI-X: Unknown
Supports Wake-on: uag
Wake-on: d
Link detected: yes