Cat 6509 automatically put VLAN state into "suspended" and killed my network...why?

Discussion in 'Cisco' started by rpfiberguy@gmail.com, Jan 23, 2007.

  1. Guest

    Any ideas what would cause a CAT 6509 running IOS to put ALL of its
    VLAN into a suspended state? I was adding in a new edge switch and as
    soon as I turned on the port, all traffic stopped. I took me an hour
    to figure out how to change the state back to active. I'd like to
    avoid this in the future, but I don't know what caused it.
    , Jan 23, 2007
    #1
    1. Advertising

  2. Cisco 6509 VLANs disappear and connectivity is lost due to the addition
    of a new switch to the network.

    This can cause amber or flashing LEDs on all ports in a VLAN across a
    network.

    http://www.bradreese.com/cisco-big-iron-repair.htm#TROUBLESHOOTING

    VLAN Trunk Protocol (VTP) allows ease of VLAN management because it
    allows the addition or deletion of VLANs across many switches.

    VTP does not require you to make additions or deletions individually on
    each switch.

    Devices configured as VTP servers (the default) periodically send
    messages with their VLAN configuration across the VTP domain to which
    they belong.

    Each time a VLAN is deleted or added on a switch, the config revision
    number is increased.

    The addition of a switch to a network within a VTP domain can cause
    lost connectivity across that network.

    This happens because the newly introduced switch has a higher config
    revision number than that of the VTP domain.

    The other switches adopt its VLAN configuration.

    The VLAN configuration of the new switch does not match the other
    switches.

    Since the new addition has the highest config revision number, all of
    the other switches configured as a VTP client or server in the VTP
    domain modify their VLAN configurations to match.

    This behavior can lead to the deletion of numerous VLANs, a loss of
    connectivity across the network, and the ports can become inactive.

    This most commonly occurs when the new switch was previously tested in
    a lab setting where repeated VLAN modifications were made.

    If precautions are not taken before the switch is connected to the
    production network, what is normally a beneficial feature causes a
    major issue.

    ------------------------------------

    To remedy the situation, perform this procedure:

    Step 1. If the links are down for ports because they are assigned to
    VLANs that no longer exist, put the switch(es) into VTP transparent
    state and manually configure the VLANs.

    This results in immediate recovery.

    Step 2. Verify that the current VTP core server has the needed VLANS,
    and is connected to the rest of the switches through trunked ports that
    are:

    - Allowed on those trunks.

    - Allowed and active in management domain.

    - In spanning tree forwarding state and not pruned.

    Note: If the clients are still in the same VTP domain, and trunked
    correctly, ideally VTP messages traverse that VTP domain.

    Step 3. If problems persist, reload the switch and configure it
    manually in order to restore connectivity.

    Note: Always verify a switch's VTP configuration before connecting it
    to a production network.

    If the switch has been previously configured or used elsewhere, it
    might already be in VTP server or client mode with a VTP configuration
    revision number that is higher than other switches in the production
    VTP domain.

    In that case, other switches will listen and learn from the new switch
    because it has a higher revision number and must know more recent
    information.

    This could cause the new switch to introduce bogus VLANs into the
    domain or, worse yet, to cause all other switches in the domain to
    delete all their active VLANs.

    In order to prevent over-writing the VTP network whenever a new switch
    is added in the future, always take these precautions:

    Step 1. Reset the configuration revision number so that it is lower
    than that of the rest of the VTP domain with these steps.

    A: Change the VTP domain of the new switch to a bogus and nonexistent
    VTP domain name, and then change the VTP domain back to the original
    name.

    B: Change the VTP type from server (the default) to transparent, and
    then change the mode back to client or server.

    Step 2. Physically connect the switch to the network.

    For additional information on this issue, including step-by-step
    instructions, refer to:

    How a Recently Inserted Switch Can Cause Network Problems

    http://www.cisco.com/en/US/tech/tk3...ech_note09186a0080094c52.shtml#vtp_ts_rec_ins

    Section of the document:

    Understanding and Configuring VLAN Trunk Protocol (VTP)

    http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080094c52.shtml

    Hope this helps.

    Brad Reese
    http://www.BradReese.Com
    www.BradReese.Com, Jan 24, 2007
    #2
    1. Advertising

  3. In article <>,
    <> wrote:
    > Any ideas what would cause a CAT 6509 running IOS to put ALL of its
    > VLAN into a suspended state? I was adding in a new edge switch and as
    > soon as I turned on the port, all traffic stopped. I took me an hour
    > to figure out how to change the state back to active. I'd like to
    > avoid this in the future, but I don't know what caused it.


    Might the edge switch have been a VTP server, and it was introduced onto
    the network with a higher revision number than the VTP database on the
    Cat6k?

    Simnply enforcing a VTP password will usually protect against this.

    Cheers,

    Matt

    --
    Matthew Melbourne
    Matthew Melbourne, Jan 24, 2007
    #3
    1. Advertising

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

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Mr_Magoo
    Replies:
    6
    Views:
    13,073
    Mr_Magoo
    May 8, 2004
  2. Kenneth

    External USB drives "suspended"...?

    Kenneth, Oct 18, 2003, in forum: Computer Support
    Replies:
    3
    Views:
    4,453
    Kenneth
    Oct 19, 2003
  3. samuel

    ebay account suspended

    samuel, May 26, 2007, in forum: Computer Support
    Replies:
    9
    Views:
    365
    SgtMinor
    May 26, 2007
  4. pbs
    Replies:
    5
    Views:
    298
  5. dany82

    Orkut Account Suspended

    dany82, Jan 30, 2010, in forum: Computer Support
    Replies:
    4
    Views:
    858
    Desk Rabbit
    Feb 3, 2010
Loading...

Share This Page