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Forum Replies

  1. Hi Rene, excelent post.
    However, I have some doubts about this topic. I read that using RSTP we have some improvements similar to Uplink and Backbone Fast. So, we don´t have to use this features on RSTP. Is that correct?

    This output was taken from a Cat3750: “UplinkFast is enabled but inactive in rapid-pvst mode”
    Can you help me with this??

    Whatever, your example is fantastic.

  2. Hlw Rene,

    Nice explanation in right WAY, GREAT !

    So , if we use Uplinkfast then no downtime occure ?? So how SWITCHC will update its MAC table as SWITCHB updated its MAC table using Multiicast Frame sending by SWITCHC ? I think there is 15 sec downtime needed due MAC table flush in SWITCHC.

    Another Questions …After STP convergence , Only Root Bridge will send BPDU(Hello time interval) and other SWITCH will receive BPDU [if no Topology Chage].


  3. Hello florian.

    To answer your first question:

    But this is only the case if uplink-fast is configured, right?
    If it is not configured the port would stay in block state for 20 sec and then move through the other states!?

    Yes, my description in the above post is for situations where uplinkfast is not implemented. In case uplinkfast is configured, this is reduced from 30 seconds to almost 0 seconds. Cisco explains it like so:

    The UplinkFast feature is based on the definition of an uplink group. On a given switch, the uplink group consists of the root port and al
    ... Continue reading in our forum

  4. Hello Maodo

    In the TCN lesson, it mentions that there will be a maximum of 50 seconds

    ... Continue reading in our forum

  5. Hello Maodo

    The link failure is also detected on SW1 however, the example examines the behaviour of the ports on SW3.

    In the diagram, @ReneMolenaar still has the (D) showing up on port fa0/17 on SW1,

    ... Continue reading in our forum

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