How to disable MSTP Spanning Tree for specifc VLAN?

Unanswered Question
Aug 4th, 2010


How do I disable MSTP Spanning Tree for specifc VLAN?  The "no span vlan #" command doesn't work.  Does MSTP not support it?

Thanks in advance.

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Sebastian Helmer Wed, 08/04/2010 - 03:30


you can delte a VLAN from the MST konfiguration with:

no instance instance-id vlan vlan-range

This must be done on every switch which is in the same instance.

Best regards,


krahmani323 Wed, 08/04/2010 - 05:10

Hello Ivan!

For PVST(+)/RPVST an instance of STP is running for each VLAN (as the number of VLANs increases, so does the number of independent STP instances).

In these two modes and just like you specified we can disable stp per vlan (no span vlan #)

Unlike PVST(+)/RPVST the whole idea behind MST is the capability to map multiple VLANs to a smaller number of STP instances.

With that being said, MST "deals" with MSTI Instaces and not directly with VLANs.

Each VLAN is mapped with an instance => By default, all VLANs are mapped to the IST (MSTI 0) instance. You can explicitly map them
to other instances, if needed.

That is the reason why I do not think we can disable MST on a vlan basis like pvst/rstp as MST operates with instances.

Hello Sebastian, I think in fact "no instance instance_id [vlan vlan_range] " will return to the default VLAN-to-instance map

For example if vlan 100 is mapped to instance 1, the command no instance 1 vlan 100 will return vlan 100 to his default instance MSTI0 (IST).


You can check that with the command show spanning-tree mst before and after.

Example :

##### MST0    vlans mapped:   1-9,11-19,21-29,31-39,41-99,101-199,201-4094
##### MST1    vlans mapped:   10,30,100

Kind regards

Sebastian Helmer Wed, 08/04/2010 - 05:43

Hi Karim,


right I forgott that.

I will think about it, maybe we find a solution.



This Discussion