Macintosh: Output of Ifconfig

Posted on 2011-10-06
Last Modified: 2012-05-12
1) I am used to with the Microsoft Window and (a little bit of) Linux Operating system
2) I am not familiar with the Macintosh OS
3) I saw some MacBook (The OS is Mac OS X 10.6.8) at a company (production environment)

4) I take one of the MacBook, and do the followings:
-Go to Utilities, and open the "terminal"
- I type in: ifconfig
- There 7 items appeared (I do not understand "these terms"; i just understand a little bit of it)

5) The 7 items are as the followings:
i) lo0
ii) gif0
iii) en0
iv) en1
v) vnic0
vi) vnic1
vii) csctun0

6) Would you somebody explain "the above terms": what is it and its function

7) Thank you
Question by:tjie
    LVL 9

    Assisted Solution

    You can find information about various Network Interfaces on your Mac Machine by Navigating Apple Menu

    - Option-clicking the Apple menu and choosing System Profiler.
    - Click on Network

    You will find that on right side there is list of various active Network Services, and information such as Network Type, Hardware, BSD Device Name (this is the name you will find in ifconfig output), and assigned IP Address if any.

    For Quick ref
    lo0 - Loopback Adapter
    en0... - Ethernet Adapters

    Hope this helps.
    LVL 21

    Accepted Solution

    i) lo0 -- loopback interface
    ii) gif0 -- IPv4 <-> IPv6 tunnel interface
    iii) en0 -- wired ethernet interface
    iv) en1 -- wired ethernet interface
    v) vnic0 -- virtual interface
    vi) vnic1 -- virtual interface
    vii) csctun0 --  some sort of tunnel interface, perhaps related to gif0 or vnic0/1 -- have never seen that before

    Author Comment

    Hi pritamdutt,

    1) I understood "ethernet adapters" (with the RJ45 port)

    2) Would you explain (with your own wording) the followings please:

    - What is "Loopback Adapter"? (What port is it related to?)
    - What about "cscotun0"? (What is iis function?) (What port is it related to?)

    3) Thank you

    LVL 21

    Assisted Solution

    At first you said csctun0, not cscotun0 -- that is an interface added by a Cisco VPN client.

    BTW I posted a link to the wiki for loopback in my first answer.
    LVL 9

    Assisted Solution

    Loopback Adapter or Loopback Interface is a Virtual Interface installed on mostly all IP enabled Operating Systems. This interface is usually assigned an IP Address of

    If you would remember, we normally ping to in order to test IP Configuration of System.

    You could further read about Loopback Adapter on wikipedia :

    As regards to cscotun0, it appears that your system has Cisco AnyConnect Secure Mobility Client installed, and this is an virtual interface created by the software to
    - create an SSL connection to a gateway running IOS, or
    - when the AnyConnect client attempts to create an IPsec connection to an ASA, from behind certain types of routers, such as the Cisco Virtual Office (CVO) router

    Hope this helps..

    Author Comment

    Hey PaperTrip,

    1) Would you explain it (with your own wording) --> What is "Loopback Adapter"? (What port is it related to?)

    2) Thanks

    LVL 21

    Assisted Solution

    Anything I would say with my own words is written better at

    There is no port involved, it's a virtual interface just like Pritam and wikipedia say :)

    Featured Post

    Free Trending Threat Insights Every Day

    Enhance your security with threat intelligence from the web. Get trending threat insights on hackers, exploits, and suspicious IP addresses delivered to your inbox with our free Cyber Daily.

    Join & Write a Comment

    In this article we will discuss some EI Capitan Mail app issues and provide some manual process to resolve them.
    This is a short article about OS X KeRanger, and what people can do to get rid of it.
    how to add IIS SMTP to handle application/Scanner relays into office 365.
    In this sixth video of the Xpdf series, we discuss and demonstrate the PDFtoPNG utility, which converts a multi-page PDF file to separate color, grayscale, or monochrome PNG files, creating one PNG file for each page in the PDF. It does this via a c…

    746 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    17 Experts available now in Live!

    Get 1:1 Help Now