What causes LOOP_BACK?

Discussion in 'Cisco' started by Craig Tranfield, Dec 15, 2003.

  1. Every now and then I have been getting...

    %ETHCNTR-3-LOOP_BACK_DETECTED: Loop-back detected on
    GigabitEthernet0/1. The port is forced to linkdown.

    Any ideas what it means?

    Thanks,

    Craig
     
    Craig Tranfield, Dec 15, 2003
    #1
    1. Advertising

  2. Craig Tranfield

    Ivan Guest

    "Craig Tranfield" <> wrote in message
    news:brkam2$62n$...
    > Every now and then I have been getting...
    >
    > %ETHCNTR-3-LOOP_BACK_DETECTED: Loop-back detected on
    > GigabitEthernet0/1. The port is forced to linkdown.
    >
    > Any ideas what it means?
    >


    Simple search on CCO:

    <CCO>
    Error Message ETHCNTR-3-LOOP_BACK_DETECTED:, Loop-back detected on
    [chars]. The port is forced to linkdown.

    Explanation This message means that the loop-back condition might be
    caused by a balun cable being accidentally plugged into the port. [chars] is
    the port.

    Recommended Action Check the cables. If a balun cable is connected and the
    loopback condition is desired, no action is required. Otherwise, connect the
    correct cable, and bring the port up by entering the no shutdown interface
    configuration command.

    </CCO>

    Ivan
     
    Ivan, Dec 15, 2003
    #2
    1. Advertising

  3. Craig Tranfield

    Steinar Haug Guest

    ["Ivan"]

    | > %ETHCNTR-3-LOOP_BACK_DETECTED: Loop-back detected on
    | > GigabitEthernet0/1. The port is forced to linkdown.
    | >
    | > Any ideas what it means?
    | >
    |
    | Simple search on CCO:

    And the CCO answer is in most cases utterly useless. Check out

    http://groups.google.com/groups?ie=...id=<>&lr=&hl=no

    for a more detailed explanation on this problem that I posed in
    October. Short version: You've probably seen a short-lived
    spanning tree problem.

    Steinar Haug, Nethelp consulting,
     
    Steinar Haug, Dec 15, 2003
    #3
  4. In article <>,
    >And the CCO answer is in most cases utterly useless.


    precisely, I had already tried that. Reference to "has wrong cable
    be plugged in" for example being irrelevant when the cables have
    been plugged in for the last 16 hours fine and then without physical
    change becomes a problem.


    >http://groups.google.com/groups?ie=...id=<>&lr=&hl=no
    >


    That is so the case!
    Why on earth don't Cisco include it in their explanation.

    Thanks,

    Craig
     
    Craig Tranfield, Dec 15, 2003
    #4
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Dave Ploch

    Roaming causes database to drop connection

    Dave Ploch, Nov 11, 2004, in forum: Wireless Networking
    Replies:
    4
    Views:
    853
    Dave Ploch
    Nov 18, 2004
  2. David Leslie

    USR2216 WiFi card causes Win XP to crash - newbie need help!

    David Leslie, Jan 16, 2005, in forum: Wireless Networking
    Replies:
    3
    Views:
    960
    David Leslie
    Jan 22, 2005
  3. Ian

    Belkin wireless card causes XP to freeze

    Ian, Mar 31, 2005, in forum: Wireless Networking
    Replies:
    5
    Views:
    7,160
  4. Keyser
    Replies:
    1
    Views:
    478
    Jack \(MVP\)
    May 10, 2005
  5. =?Utf-8?B?R2VycnlL?=

    Upgrade to WinXP SP2 causes loss of USB adapter wireless connectio

    =?Utf-8?B?R2VycnlL?=, Jul 25, 2005, in forum: Wireless Networking
    Replies:
    4
    Views:
    830
    =?Utf-8?B?R2VycnlL?=
    Jul 27, 2005
Loading...

Share This Page