I'm not sure if these have a name, but on most computers I use the interface prefixes are usually:

  • eth- : Ethernet/Wired
  • wlan- : Wireless/WiFi

However, on my ASUS RT-N56U, I have the following:

  • br0 : 'Ethernet' - Bridge?
  • eth2 : 'Ethernet', IPv6 (where are 0 and 1?)
  • eth3 : 'Ethernet', IPv4 (the one with my WAN IP)
  • lo : 'Local Loopback' - What's this for?
  • ra0 : 'Ethernet' - ?
  • rai0 : 'Ethernet' - ?

Are there others? What do they mean?

  • Also, 'em*', please.
    – JS.
    Sep 14 at 23:42

3 Answers 3


From the ASUS RT-N56U wiki page:

What are the existing network interfaces (transcript naming interfaces)?

    br0 = LAN + WLAN + AP-Client + WDS
    eth2 = Ethernet interface GMAC1, that connected to the switch (trunk port).
    eth2.1 = LAN (VLAN VID1)
    eth2.2 = WAN (VLAN VID2)
    ra0 = WLAN 5GHz
    ra1 = WLAN 5GHz Guest
    rai0 = WLAN 2.4GHz
    rai1 = WLAN 2.4GHz Guest
    apcli0 = AP-Client 5GHz
    apclii0 = AP-Client 2.4GHz
    wds0-wds3 = WDS 5GHz
    wdsi0-wdsi3 = WDS 2.4GHz 

In the no-VLAN firmware

    eth2 = LAN
    eth3 = WAN 
  • 1
    Thanks for the list, I was really hoping there was some 'standard', but in lieu of one, this explains my particular case.
    – Ehryk
    Jun 25, 2013 at 20:54

They mean whatever the driver designer wanted them to mean. There are many many others too, like ib0 for Infiband devices. But I am not aware of anywhere that has a complete list as again it depends on who develops the driver as to what the name of the device is. Usually it gives some clue as to the type of board but that is about it. The number after the device designation is generally used to indicate which of several ports/devices the device is.

  • Any insight into br, lo, ra and rai?
    – Ehryk
    Jun 25, 2013 at 4:37
  • have you googled around? You might find the answer. lo is the loopback driver (handler for ethernet address).
    – mdpc
    Jun 25, 2013 at 4:38
  • Confirm that lo is loopback (connecting to your own computer doesn't require a real Ethernet interface, so the kernel has a special fake interface for this) and br is bridge (you create one with brctl).
    – tripleee
    Jun 25, 2013 at 4:49
  • I've seen both wlan and wifi for wireless. On Ubuntu the bare interface comes up as wlan0 but MDNS and what not creates some wrappers and you see the virtual interface wifi0 instead.
    – tripleee
    Jun 25, 2013 at 4:52
  • Some hardware gets a specific ethX number by udev rules. You might have rules in place which assign your eth3 and eth4 cards so that you know which is which (different speed, different hardware, different drivers, whatever).
    – tripleee
    Jun 25, 2013 at 4:53

You can see all interfaces using ifconfig -a or ip address show; It will show them even they are down.

  • 2
    On my particular machine, yes. That's not what I'm interested in - I'm asking what the prefixes mean across all machines, I.E. eth- usually means ethernet, wlan- or wifi- usually mean wireless, and I'm asking what the rest are.
    – Ehryk
    Jun 25, 2013 at 20:51

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