HP ProCurve Series 3400cl Release Notes page 148

Enhancements
Release M.10.65 Enhancements
Each MST instance supports a different set of VLANs. A VLAN that is mapped to an MST instance
cannot be a member of another MST instance.
The MSTP VLAN Configuration enhancement allows you to ensure that the same VLAN ID-to-MSTI
assignments exist on each MSTP switch in a region. Before a static VLAN is configured or a dynamic
VLAN is learned on the switch, you can use the spanning-tree instance vlan command to map VLANs
to each MST instance in the region. Later, when the VLAN is created, the switch automatically assigns
it to the MST instance to which you had previously mapped it.
Syntax: [no] spanning-tree instance < 1..16 > vlan < vid [ vid..vid ] >
no spanning-tree instance < 1..16 >
Configuring MSTP on the switch automatically configures the IST instance and
places all statically and dynamically configured VLANs on the switch into the IST
instance. This command creates a new MST instance (MSTI) and moves the VLANs
you specify from the IST to the MSTI.
You must map at least one VLAN to an MSTI when you create it. You cannot map
a VLAN ID to more than one instance. You can create up to 16 MSTIs in a region.
The no form of the command removes one or more VLANs from the specified MSTI.
If no VLANs are specified, the no form of the command deletes the specified MSTI.
When you remove a VLAN from an MSTI, the VLAN returns to the IST instance,
where it can remain or be re-assigned to another MSTI configured in the region.
Note: The valid VLAN IDs that you can map to a specified MSTI are from 1 to 4094.
The VLAN ID-to-MSTI mapping does not require a VLAN to be already configured
on the switch. The MSTP VLAN enhancement allows you to preconfigure MSTP
topologies before the VLAN IDs associated with each instance exist on a switch.
When you use preconfigured VLAN ID-to-MSTI topologies, ensure that MSTP
switches remain in the same region by mapping all VLAN IDs used in the region
to the same MSTIs on each regional switch.
Configuring MSTP Instances with the VLAN Range Option
If you use the spanning-tree instance command with the VLAN range option, even if the range includes
VLANs that are not currently present on the switch, the entire range of VLANs is configured. For
example, if VLANs 1, 5, and 7 are currently present and you enter this command:
ProCurve(config)# spanning-tree instance 1 vlan 1-10
then all the VLANs from 1 through 10 are included, even those VLANs that are not present.
Figure 23 shows an example of an MSTP instance configured with the VLAN range option. All the
VLANs are included in the instance whether they exist or not.
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