Random mac address assigned voor BVI ?

Discussion in 'Cisco' started by Ronald de Leeuw, Oct 5, 2004.

  1. When my BVI interface comes up I get the following :

    Mar 1 01:21:54.267:
    Note: A random mac address of 0000.0cf6.0dc4
    has been chosen for BVI in bridge group 10 since there is no mac
    address
    associated with the selected interface.
    Mar 1 01:21:54.271:
    Ensure that this address is unique.

    Mar 1 01:22:05.244:
    Note: A random Spanning Tree Bridge Identifier address of 0000.0cee.38a4
    has been chosen for Bridge Group 10 since there is no mac address
    associated with the selected interface.
    Mar 1 01:22:05.244:
    Ensure that this address is unique.

    How do I configure this mac address and spanning tree bridge identifier
    static in my router?

    Ronald de Leeuw
     
    Ronald de Leeuw, Oct 5, 2004
    #1
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  2. Ronald,
    I am not sure if the mac-address and spanning tree bridge identifier can
    be hardcoded on a BVI. My question, out of curiousity, is why would you want
    to?

    It is my understanding that the BVI is going to borrow a mac address from
    one of the interfaces in the bridge group, which would make sense since you
    want the bridge group to be "seen" at layer 2 i.e. have a mac that is valid
    in the CAM. Also, it is my understanding that from a spanning-tree
    perspective the BVI will have it's own instance of spanning-tree much like a
    VLAN does so I do not see the utility in hardcoding the bridge identifier
    either.

    Maybe clarifying what you are trying to accomplish will help the group
    provide an acceptable solution?

    Good Luck
    -Robert
     
    Robert B. Phillips, II, Oct 6, 2004
    #2
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  3. Ronald de Leeuw

    Ivan Ostreš Guest

    Let's see how does it work:

    RouterB#
    RouterB#
    RouterB#conf t
    Enter configuration commands, one per line. End with CNTL/Z.
    RouterB(config)#bridge irb
    RouterB(config)#int eth0/0
    RouterB(config-if)#bridge
    RouterB(config-if)#bridge-group 1
    RouterB(config-if)#int bvi 1
    RouterB(config-if)#mac-address ?
    H.H.H MAC address

    RouterB(config-if)#mac-address 00aa.00bb.00cc
    RouterB(config-if)#
    RouterB(config-if)#end
    RouterB#
    RouterB#
    RouterB#sh int bvi 1 | incl Hardw

    Hardware is BVI, address is 00aa.00bb.00cc (bia 0000.0000.0000)

    RouterB#


    Seems it's possible to add a MAC address to BVI and looks ok..
     
    Ivan Ostreš, Oct 6, 2004
    #3
  4. Ronald de Leeuw

    Hansang Bae Guest

    Because BVI is full of bugs if you don't hardcode MACs. Well, to be
    fair, I should say that 8540's implementation of BVIs is faulty at best.


    --

    hsb

    "Somehow I imagined this experience would be more rewarding" Calvin
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    Hansang Bae, Oct 6, 2004
    #4
  5. Ah, I don't have that much experience with BVI outside of xDSL PPPoA
    configs, so I was not aware. Thanks...
     
    Robert B. Phillips, II, Oct 9, 2004
    #5
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