Displaying Network Interface Status

Use the –i option of the netstat command to display the state of the network interfaces that are configured on a local system. With this option, you can determine the number of packets a system transmits and receives on each network.

Display the status of the interfaces that are on a network as follows:

% netstat -i

The following example shows how you would use the netstat command with a filtering option to limit the output of a specific interface:

% netstat -i -I net0 -f inet
  Name  Mtu  Net/Dest      Address        Ipkts  Ierrs Opkts  Oerrs Collis Queue 
  net0  1500 abc.oracle.com abc.oracle.com 231001 0     55856  0     0      0     

The following example shows the status of IPv4 and IPv6 packet flow through the host's interfaces. For example, the input packet count (Ipkts) that is displayed for a server can increase each time a client tries to boot, while the output packet count (Opkts) remains steady. This outcome suggests that the server is recognizing the boot request packets from the client. However, the server does not know to respond to them. This confusion might be caused by an incorrect address in the hosts, or ethers database.

If the input packet count is steady over time, then the machine does not see the packets at all. This outcome suggests a different type of failure, possibly a hardware problem.

Name  Mtu  Net/Dest      Address        Ipkts  Ierrs Opkts  Oerrs Collis Queue
lo0   8232 loopback      localhost      142    0     142    0     0      0
net0  1500 host58        host58        1106302 0     52419  0     0      0

Name  Mtu  Net/Dest      Address                    Ipkts  Ierrs Opkts  Oerrs Collis
lo0   8252 localhost     localhost                   142    0     142    0     0
net0  1500 fe80::a00:20ff:feb9:4c54/10 fe80::a00:20ff:feb9:4c54 1106305 0 52422 0  0