Help with switch configuration, ( 3 3550's, 5 2950's end to end )

Discussion in 'Cisco' started by ec, Aug 23, 2004.

  1. ec

    ec Guest

    I am connecting via fiber 8 switches out on a Texas railway. It looks like
    this:

    3550-2950-2950-2950-3550-2950-2950-3550 <-- then this 3550 has another pair
    going straight back to the 1st 3550, to create a redundant path.

    That is an 8 switch diameter, and concerned with STP. The 3550's have EMI
    images so I have flexibility there. What would you recommend for this as far
    as configuration? My goal is that if any fiber link and/or switch breaks, an
    alt path exists. Since STP diameter is large than 7 I suppose I cannot just
    rely on layer 2 and should break these up into layer 3 somehow?
     
    ec, Aug 23, 2004
    #1
    1. Advertisements

  2. ec

    Steinar Haug Guest

    ["ec"]

    | That is an 8 switch diameter, and concerned with STP. The 3550's have EMI
    | images so I have flexibility there. What would you recommend for this as far
    | as configuration? My goal is that if any fiber link and/or switch breaks, an
    | alt path exists. Since STP diameter is large than 7 I suppose I cannot just
    | rely on layer 2 and should break these up into layer 3 somehow?

    Layer 3 is often a good choice. You may also want to look into Rapid
    Spanning Tree (RSTP, 802.1w) which doesn't have the 7 hop limit of
    standard 802.1d STP - and also gives you much faster rerouting.

    Cisco Per-VLAN RSTP is a breeze to configure (just turn it on) as long as
    all the switches support it.

    Steinar Haug, Nethelp consulting,
     
    Steinar Haug, Aug 23, 2004
    #2
    1. Advertisements

  3. ec

    ec Guest

    Damn, spanning-tree mode rapid is your friend! Thanks, I never knew 2950G
    supported per vlan rapid-stp. Cisco docs say it doesn't, but the command is
    there and it does work. What are the limitations of RSTP?
     
    ec, Aug 23, 2004
    #3
  4. ec

    shinobi

    Joined:
    Jul 25, 2006
    Messages:
    1
    Likes Received:
    0
    Hi ,

    Can you refer me to resource or url of this comment : ( 802.1w does not have 7 hop limit)

    --------quote----------
    Layer 3 is often a good choice. You may also want to look into Rapid
    Spanning Tree (RSTP, 802.1w) which doesn't have the 7 hop limit of
    standard 802.1d STP - and also gives you much faster rerouting.


    Thanks
     
    shinobi, Jul 25, 2006
    #4
    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.