Sample configuration of using (MSTP) feature on 3560

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May 7th, 2006
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I have 3560 switch running PVST, performing purely as layer 2 vlans, I already reached 120 vlans so I will be running out of spantree soon.

I would like to have a sample configuration of using (MST) feature to map multiple vlans to a single vlan to minimize my maximum spantree per vlan usage.

Any sample config would be highly appreciated.


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Overall Rating: 5 (1 ratings)
ankurbhasin Sun, 05/07/2006 - 21:13
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Hi Friend,

Have a look at this

Switch(config)# spanning-tree mst configuration

Switch(config-mst)# instance 1 vlan 10-20

Switch(config-mst)# name region1

Switch(config-mst)# revision 1

But I will recommend you to go through the complete link below to get full idea of MST before implementing in your network.

HTH,if yes please rate the post


Mohamed Sobair Sun, 05/07/2006 - 22:35
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Hi Ankur,

Thank you for your input, I have one doubt and i just want to make sure about it,

My Switch is 3560G TS-S, running in PVST mode, I have configured 120 vlans, How many Spantree instance support per one vlan?? is it 128 ....

Another issue, do I have to enable MST if I am going to configure more than 128 vlans on both Identical/Redundant 3560 Switches performing as layer 2 or no need for that??

Appreciate your kind help,

Thank you,

ankurbhasin Sun, 05/07/2006 - 22:46
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Hi Friend,

Yes 3560 on PVST+ mode supports 128 vlan only. So only 128 vlans can be configured for per spanning tree instance.

If you are going above 128 VLAN then yes you should plan to configure MST for all the switches who will be having more than 128 VLAN which means your both switches should be configured for MST.

HTH, if yes please rate all post.



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