CISCO 2950 could forward Spanning Tree Protocol BPDUs? Is this right?

Discussion in 'Cisco' started by wade, Dec 16, 2003.

  1. wade

    wade Guest

    Dear Sir:

    Recently,i am studying "The Switch
    Book"(bookstore:'WIERLY',author:'')and IEEE 802.1D.

    First, in this "The Switch Book" book,page.103, it said that "any of
    the protocols that use these address,the bridge must not forward or
    flood frames sent to any reserved address" and the reserved address
    are "01-80-c2-00-00-00 ,01-80-c2-00-00-01 ,01-80-c2-00-00-02
    ,01-80-c2-00-00-03 ,.....01-80-c2-00-00-0F ".
    Second,in 802.1D 2003, 7.12.6 Reserved addresses:
    "Frames containing any of the group MAC Addresses specified in Table
    7-10 in their destination address field shall not be relayed by the
    Bridge. They are configured in the Permanent Database. Management
    shall not provide the capability to modify or remove these entries
    from the Permanent or the Filtering Databases. These group MAC
    Addresses are reserved for assignment to standard protocols, according
    to the criteria for such assignments (Clause 5.5 of ISO/IEC TR
    11802-2)." in Table7-10,there are some information about reserved
    addresss which are "01-80-c2-00-00-00 ,01-80-c2-00-00-01
    ,01-80-c2-00-00-02 ,01-80-c2-00-00-03 ,.....01-80-c2-00-00-0F ".

    But when i use PC and network analysis tools(such as Sniffer)to send
    RSTP BPDUs(to pretend my PC is a switch),and to cpature frames from
    CISCO2950. I disabled STP or RSTP or MSTP protocol(function) in all
    VLAN which are exist in Cisco,i still captured RSPT BPDUs from CISCO.
    Could someone please tell why Cisco doesn't follow the IEEE
    standard,or some other reasons that switch isn't necessarily to follow
    the standard?

    Best Regardly 2003.12.16
    wade, Dec 16, 2003
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