Nothing Special   »   [go: up one dir, main page]
Scribd Logo
Upload

Welcome to Scribd!

  • 43 views

    Unidirectional Link Detection (Udld

    Uploaded by

    ziad Al-showaiter
    UniDirectional Link Detection (UDLD) allows devices to detect unidirectional links and disable ports to avoid problems such as spanning tree loops. UDLD works with Layer 1 mechanisms to detect physical link status and identify neighbors, going beyond autonegotiation. In normal mode, a disconnected fiber strand will not cause the link to stay up, but UDLD takes no action; in aggressive mode, UDLD can detect unidirectional ports in additional cases and disable the affected port.

    Copyright:

    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd

    Unidirectional Link Detection (Udld

    Uploaded by

    ziad Al-showaiter
    43 views2 pages
    UniDirectional Link Detection (UDLD) allows devices to detect unidirectional links and disable ports to avoid problems such as spanning tree loops. UDLD works with Layer 1 mechanisms to detect physical link status and identify neighbors, going beyond autonegotiation. In normal mode, a disconnected fiber strand will not cause the link to stay up, but UDLD takes no action; in aggressive mode, UDLD can detect unidirectional ports in additional cases and disable the affected port.

    Original Description:

    Original Title

    UDLD

    Copyright

    © © All Rights Reserved

    Available Formats

    DOCX, PDF, TXT or read online from Scribd

    Did you find this document useful?

    Is this content inappropriate?

    UniDirectional Link Detection (UDLD) allows devices to detect unidirectional links and disable ports to avoid problems such as spanning tree loops. UDLD works with Layer 1 mechanisms to detect physical link status and identify neighbors, going beyond autonegotiation. In normal mode, a disconnected fiber strand will not cause the link to stay up, but UDLD takes no action; in aggressive mode, UDLD can detect unidirectional ports in additional cases and disable the affected port.

    Copyright:

    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd
    Download as docx, pdf, or txt
    43 views2 pages

    Unidirectional Link Detection (Udld

    Uploaded by

    ziad Al-showaiter
    UniDirectional Link Detection (UDLD) allows devices to detect unidirectional links and disable ports to avoid problems such as spanning tree loops. UDLD works with Layer 1 mechanisms to detect physical link status and identify neighbors, going beyond autonegotiation. In normal mode, a disconnected fiber strand will not cause the link to stay up, but UDLD takes no action; in aggressive mode, UDLD can detect unidirectional ports in additional cases and disable the affected port.

    Copyright:

    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd
    Download as docx, pdf, or txt
    of 2

    UniDirectional Link Detection (UDLD

    - When UDLD detects a unidirectional link, it disables the affected port and alerts you.
    Unidirectional links can cause a variety of problems, including spanning-tree topology loops.
    -
    - In normal and aggressive modes, UDLD works with the Layer 1 mechanisms to learn the physical
    status of a link. At Layer 1, autonegotiation takes care of physical signaling and fault detection.
    UDLD performs tasks that autonegotiation cannot perform, such as detecting the identities of
    neighbors and shutting down misconnected ports .
    -
    - When UDLD is in normal mode, if one of the fiber strands in a pair is disconnected, as long as
    autonegotiation is active, the link does not stay up because the Layer 1 mechanisms detects a
    physical problem with the link. In this case, UDLD does not take any action and the logical link is
    considered undetermined.
    - In aggressive mode, UDLD detects a unidirectional link by using the previous detection methods.
    UDLD in aggressive mode can also detect a unidirectional link on a point-to-point link on which
    no failure between the two devices is allowed. It can also detect a unidirectional link when one
    of these problems exists:

     On fiber-optic or twisted-pair links, one of the ports cannot send or receive traffic.
     On fiber-optic or twisted-pair links, one of the ports is down while the other is up.
     One of the fiber strands in the cable is disconnected.
    In these cases, UDLD disables the affected port.

    Purpose
    Command
    Step 1 configure terminal Enter global configuration mode.
    Step 2 interface interface-id Specify the port to be enabled for UDLD, and enter interface
    configuration mode.
    Step 3 udld port [ aggressive] UDLD is disabled by default.
    Note When a switch joins a switch stack, it retains its interface-specific
    UDLD settings.
    udld port —Enables UDLD in normal mode on the specified
    port.
    udld port aggressive —Enables UDLD in aggressive mode
    on the specified port.
    Note Use the no udld port interface configuration command to disable
    UDLD on a specified fiber-optic port.

    Step 4 end Return to privileged EXEC mode.


    Step 5 show udld interface-id Verify your entries.

    You might also like