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Forum Replies

  1. Wow. Excellent lesson. Very clear and to the point. I am definetly enjoying this site and learning. Excellent refresher cource !
    Please keep up the great work. BTW…Yes I am recommonding this site.

  2. Hi Srini,

    When a non-edge or root port moves into the forwarding state then this triggers as topology change in RSTP. When this happens it will start the TC while timer which 2x hello (4 seconds in total) and it will flush the MAC addresses that were learned on all non-edge interfaces.

    When the TC while timer is active, all BPDUs that the switch will send will have the TC bit set. Other switches that receive this BPDU will start their own TC while timer and they will flush all MAC addresses except the interface where they received the BPDU with the TC bit.

    I hope this helps.


  3. Hi John,

    That’s correct, RSTP has features that are similar to uplinkfast and backbonefast, there’s no need to activate these.


  4. Hello Azeem! I will attempt to answer your questions one by one:

    Question 1.1: In RSTP, I powered on 3 Switches, now all the 3 switches trying to select the Root bridge,In this process will they send proposal bit set in their BPDUs or not?

    Selection of the root bridge in RSTP IS similar to STP. RSTP still uses the best bridge ID (Priority + MAC address) to determine the root bridge. And yes, the proposal bit will be set in their BPDUs. The purpose of the proposal bit however, is not to find the root bridge, but to allow for the sync process, that is, to v

    ... Continue reading in our forum

  5. Hello florian

    No problem! Keep the questions coming, that’s why we’re here! :slight_smile:

    Such a switch will send BPDUs out of all STP enabled ports except blocking ports. Blocking ports will only receive BPDUs.

    I hope this has been helpful!


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