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How BDPUs work in BCM532125S

  • 1.  How BDPUs work in BCM532125S

    Posted 08-06-2019 03:21 AM
     1. BPDUs(Bridge protocol data unit) are used to transmit Spanning Tree Protocol (STP) information. Upon receiving BPDUs, will BCM53125S transparently transmit all of them or else?

     

    2. Is there a specific multicast frame which won't be transparently transmitted by BCM53125S?



  • 2.  RE: How BDPUs work in BCM532125S

    Posted 08-07-2019 01:40 AM
    Hi Kelvin,
    Please find the below comment per your two questions.
    1. Yes, BCM53125S will transparently transmit the BPDU packet. And it is configurable.
        1-1, for managed Switch as IMP port set in managed mode,
               - when Reg(0x02: 0x00) bit[1] En_Rx_BPDU is enabled, the BPDU packet will be trapped to IMP port to external CPU
               - when Reg(0x02: 0x00) bit[1] En_Rx_BPDU is disabled, the BPDU packet will be dropped
        1-2, for unmanaged Switch as IMP port set in unmanaged mode,
               - when Reg(0x00: 0x2F) bit[0] = 1, the BPDU packet will be dropped
               -
    when Reg(0x00: 0x2F) bit[0] = 0, the BPDU packet will be flooded to all ports
    2. Please check our datasheet "Behavior for Reserved Multicast Address" table, there are the list of reserved multicast addresses action on BCM53125S.

    Please let me know if there is question.

    Thanks,
    Ryan




    ------------------------------
    Master R&D Applications Engineer
    Broadcom
    ------------------------------



  • 3.  RE: How BDPUs work in BCM532125S

    Posted 08-12-2019 11:44 PM

    Thanks for detailed reply.
    It's of great help to me.