Checking Additional Network Interfaces

Checking Additional Network Interfaces

If your system has more than one network interface (additional interfaces are usually fiber-optic [FDDI] links or SLIP connections or other Ethernet boards) you can easily perform the above checks on each network interface.

To check your other network interfaces, give the netstat -in command. You see output similar to the following:

Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Coll

ec0 1500 192.70.0 192.70.0.9 15 0 15 0 24

ec1 1500 192.70.2 192.70.2.5 15 0 15 0 24

sl0 1006 (pt-to-pt) 192.70.0.9 0 0 0 0 0

lo0 8304 loopback localhost 8101 0 8101 0 0

The second Ethernet connection is to the network 192.70.2, a different LAN from the first Ethernet connection. The address of the local station on the second LAN is 192.70.2.5. To check that connection, use the ping command to test the connection to another station on that network.

There is also a SLIP link running in this example. The SLIP link extends the same LAN as ec0 to another system in a different location. To test this link, find the hostname or IP address of the station at the other end of the SLIP link and use the ping command to test connectivity.

The lo0 interface is the loopback network interface on the local host.