MST (Multiple Spanning Tree)


For this lab you need REAL hardware. You can’t use switches in GNS3!

You need at least Catalyst 2950 switches for this lab.

You are a master of spanning tree and specialized in migration scenarios. Corkscrew inc. is one of your customers and they are having issues with their switches. There are many VLANs in the network and you would like to reduce the number of spanning tree calculations. As a result you decide to implement MST (Multiple Spanning Tree) for them.


  • Configure all switches to use MST.
  • Configure VLAN 10,20,30,40,50 and 60 on all switches.
  • Configure VLAN 10,20 and 30 to use instance 1 for the spanning tree calculation.
  • Configure VLAN 40,50 and 60 to use instance 2 for the spanning tree calculation.
  • Configure SW1 to be the root bridge for the CIST.
  • Configure SW2 to be the root bridge for instance 2.

It took me 1000s of hours reading books and doing labs, making mistakes over and over again until I mastered all the switch protocols for CCNP.

Would you like to be a master of switching too? In a short time without having to read 900 page books or google the answers to your questions and browsing through forums?

I collected all my knowledge and created a single ebook for you that has everything you need to know to become a master of switching.

You will learn all the secrets about spanning-tree, MST, root bridges and more.

Does this sound interesting to you? Take a look here and let me show you how to Master CCNP SWITCH


Basic IOS for the switches should be sufficient. No special features needed.


Multi Spanning Tree Network Topology

Video Solution:

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The How to Master series helps you to understand complex topics like spanning-tree, VLANs, trunks, OSPF, EIGRP, BGP and more.

Written by René Molenaar - CCIE #41726

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About the Author: Rene Molenaar

René - CCIE #41726 is the creator of where he shares CCNA, CCNP and CCIE R&S labs. He also blogs about networking on


  1. Hi Rene
    I have done this lab and comes out that MST does not help the
    networker much,possibly the SW.The vlan needs to be configured twice and VTP can not be used,although I heard that possibly VTP 3 wil do that for MST.Otherwise the configuration is very similar to Rapid ST.I have added more features PVLANs,VLAN ACL,SPAN,Layer 3 Switching but everything was functioning with no problem.It is easy to forget to double config the vlans.
    I think this idea of combining features could be good.
    For example SW security and including port-secu,DHCP-snoo,Arp inspec,PVLANS,VLAN ACL in a single lab all running on MST or other kind of STP.
    Just an idea applicable to many others technologies

    1. Hi Gio,

      That’s interesting. I didn’t know that MST and VTP had issues. It’s definitely a good idea to create more advanced switch labs that will combine some protocols, I should create some more for sure!


      1. Hello firends.
        in addition to the topic, I would mention that I discovered the reviosion number of MSTP does not inrement itself as in VTP and I found as well that it has to be incremented on each switch in the region manually, one by one, even f there are lets say 100 switches.
        Can you, friends, answer or describe what does it meaning and my MSTP cannot increment as VTP, what is the problem or maybe specification of that? Let us agree taht it is not convenient every time open all switches and inrement reviosion even if there is only a sipmle thing is added or removed.
        Thanx in advance.

  2. Wondering if the attachment file or .zip file for MST is part of the CCNA pdf package or is it apart of the other pdf for CCNP switching. I looked to see if the file was present, but it was not.

  3. hai, how to configure mst in gns3 ….i tried several times but the command is not supporting ..please help?

    1. You can’t configure MST in GNS3, you’ll need real switches for it or you can try IOU.

    1. IOU-WEB is very useful for Switch LABS, You can configure a lot of LABS about Switch and Routing, BUT you can not configure EtherChannel for Layer 3 that you can’t set IP for a Port-Channel Lay 3 on Switch.

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