VTP questions (multiple VTP servers on same domain)

Discussion in 'Cisco' started by news8080, May 30, 2007.

  1. news8080

    news8080 Guest

    I read http://www.cisco.com/warp/public/473/21.html#pracex
    and http://www.cisco.com/univercd/cc/td/doc/product/lan/cat5000/rel_4_2/config/vlans.htm#xtocid798015
    twice and just want to run this by you guys to see if I understood it.

    1. If two switches are set as server with VTP Pruning disabled, no
    password, empty string as domain name (out of the box config.) whats
    there to stop someone to bring up a switch and call him self a master
    of the VTP domain with vtp version 2 enabled? (nothing right?)

    2. do i understand it correctly that when I make a vlan pruning-
    ineligible, it won't be 'learned' by a VTP advertisement even when the
    config. revision number is higher, in other words, if I have a switch
    with some prune-ineligible vlans defined, it doesn't matter if some
    other switch advertises a VTP advertisement with higher config. rev.
    number, I won't erase those vlans.

    3. what the best way to make sure that only set vlans are 'learned'
    via VTP?

    4. if I have multiple VTP servers on same l2 network connected via
    trunks with different VLANs on each? is that a disaster waiting to
    news8080, May 30, 2007
    1. Advertisements

  2. news8080

    Thrill5 Guest

    VTP doesn't work unless you have a VTP domain name configured. If the VTP
    domain is nothing, this is the same as VTP transparent mode.

    VTP pruning has nothing to do with VTP learning or deleting new VLANs. VTP
    pruning allows VLANs to be pruned from trunks between switches i.e. if a
    switch B connected via switch A does not have any ports with VLAN 20, VLAN
    20 would be pruned from the trunk between switch A and switch B. Its better
    to prune vlans manually using "switchport trunk allowed-vlan" command.

    The only way to make sure that vlan's are learned is to make the switch a
    "vtp client". There is nothing to prevent someone from making it "vtp
    transparent" creating a vlan and then making it "vtp client" again.

    No, every switch in your network can be a "vtp server". All this means is
    if a vlan is created on a switch that is a "vtp server", the vlan
    information will be sent to all the other switches in the same vtp domain
    and created on those switches as well.

    Thrill5, May 30, 2007
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.