How to display network interfaces in Linux Systems

On most of Linux distributions and other Unix based systems, such as Mac OS X, FreeBSD, Solaris, etc, you will find a command called “ifconfig” that will help you to view the current state of the network interfaces. This tutorial we will see how to get that information on the screen using the command line.

 

Display current state information of all the network interfaces:

 

The following output is an example from a Linux system (Ubuntu, CentOS, Debian, Redhat, Fedora, Mint, etc )

 

# ifconfig

eth0      Link encap:Ethernet  HWaddr 00:50:56:8A:43:AC  

          inet addr:192.168.1.1  Bcast:192.168.1.127  Mask:255.255.255.128

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:21748317 errors:0 dropped:0 overruns:0 frame:0

          TX packets:16457241 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000 

          RX bytes:6539594240 (6.0 GiB)  TX bytes:14298044266 (13.3 GiB)

 

lo        Link encap:Local Loopback  

          inet addr:127.0.0.1  Mask:255.0.0.0

          UP LOOPBACK RUNNING  MTU:16436  Metric:1

          RX packets:268691 errors:0 dropped:0 overruns:0 frame:0

          TX packets:268691 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:0 

          RX bytes:37088433 (35.3 MiB)  TX bytes:37088433 (35.3 MiB)

 

The case above we have the information of the first network interface (eth0) and the loopback interface (lo). In case you have many network interfaces available you can specify the interface you want to see the information.

 

# ifconfig lo

lo        Link encap:Local Loopback  

          inet addr:127.0.0.1  Mask:255.0.0.0

          UP LOOPBACK RUNNING  MTU:16436  Metric:1

          RX packets:268995 errors:0 dropped:0 overruns:0 frame:0

          TX packets:268995 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 Alle  casino  jackpotspellen Alle hot games Grootste winnaars Doe via uw internetbank een directe betaling via iDeal. txqueuelen:0 

          RX bytes:37120902 (35.4 MiB)  TX bytes:37120902 (35.4 MiB)

 

Next we will see an example of a output from a Mac OS X system:

 

$ ifconfig

lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384

    options=3<RXCSUM,TXCSUM>

    inet6 ::1 prefixlen 128 

    inet 127.0.0.1 netmask 0xff000000 

    inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 

    inet 127.94.0.1 netmask 0xff000000 

    inet 127.94.0.2 netmask 0xff000000 

    nd6 options=1<PERFORMNUD>

en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500

    options=10b<RXCSUM,TXCSUM,VLAN_HWTAGGING,AV>

    ether 68:5b:35:af:a5:fa 

    inet6 fe80::6a5b:35ff:feaf:a5fa%en0 prefixlen 64 scopeid 0x4 

    inet 192.168.1.102 netmask 0xffffff80 broadcast 192.168.1.127

    nd6 options=1<PERFORMNUD>

    media: autoselect (100baseTX <full-duplex>)

    status: active

 

Next we will see an example of a output from a FreeBSD system:

 

ifconfig

em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500

 options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>

 ether 00:0c:29:df:07:9f

 inet 192.168.1.2 netmask 0xffffff00 broadcast 192.168.1.255

 media: Ethernet autoselect (1000baseT <full-duplex>)

 status: active

em1: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500

 options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>

 ether 00:0c:29:df:07:a9

 media: Ethernet autoselect (1000baseT <full-duplex>)

 status: active

lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384

 options=3<RXCSUM,TXCSUM>

 inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3 

 inet6 ::1 prefixlen 128 

 inet 127.0.0.1 netmask 0xff000000 

 nd6 options=3<PERFORMNUD,ACCEPT_RTADV>

Display all network interfaces: 

ifconfig -a