Configuring MSTP at a glance
The general steps for configuring MSTP via the CLI are:
Configure MSTP global parameters. This involves:
Selecting MSTP as the spanning tree mode:
spanning-tree mode mstpClearing spanning tree debug counters:
spanning-tree clear-debug-countersSpecifying required parameters for MST region identity:
Region Name:spanning-tree config-nameRegion Revision Number:spanning-tree config-revisionOptionally, specifying MSTP parameter changes for region settings:
Hewlett Packard Enterprise recommends that you leave these parameters at their default settings for most networks. See the Caution below.
The maximum number of hops before the MSTP BPDU (Bridge Protocol Data Unit) is discarded:
spanning-tree max-hops(default: 20)Force-Version operation:
spanning-tree force-versionForward Delay:
spanning-tree forward-delayHello Time (if it is the root device):
spanning-tree hello-timeMaximum age to allow for STP packets before discarding:
spanning-tree maximum-ageDevice spanning tree priority. Specifies the priority value used along with the switch MAC address to determine which device is root. The lower a priority value, the higher the priority:
spanning-tree priority
Enabling SNMP traps:
[no]
spanning-tree trap{ errant-bpdu | loop-guard | new-root | root-guard }
![[CAUTION: ]](images/caution.gif)
CAUTION: When you enable MSTP on the switch, the default MSTP spanning tree configuration settings comply with the values recommended in the IEEE 802.1s Multiple Spanning Tree Protocol (MSTP) standard. Inappropriate changes to these settings can cause severely degraded network performance. Thus Hewlett Packard Enterprise strongly recommends that changing these default settings be reserved only for experienced network administrators with a full understanding of IEEE 802.1D/w/s standards and operation.
Configure per port parameters. Hewlett Packard Enterprise recommends that you use the default settings for these parameters and apply changes on a per-port basis only where a non-default setting is clearly indicated by the circumstances of individual links. Other features you might consider, include BPDU Filtering or BPDU Protection—these provide additional per-port control over spanning tree operations and security on the switch.
Configure MST instances. Configure one instance for each VLAN group that you want to operate as an active topology within the region to which the switch belongs. When you create the instance, you must include a minimum of one VID. You can add more VIDs later if desired. Use the following command:
spanning-tree instance<n>vlan<vid>To move a VLAN from one instance to another, first use
no spanning-tree instance<n>vlan<vid>to unmap the VLAN from the current instance, then add the VLAN to the other instance. (While the VLAN is unmapped from an MSTI, it is associated with the region's IST instance.)Configure the priority for each instance with the following command:
spanning-tree instance<n>priority<n>Configure MST instance port parameters. Hewlett Packard Enterprise recommends that you apply changes on a per-port basis only where a non-default setting is clearly indicated by the circumstances of individual links. For example, you might want to set the path cost value for the ist or for the ports used by a specific MST instance. Use the following command:
spanning-tree instance<ist | 1..16 port-list>path-cost [<auto>|<1..200000000>]Alternatively, leaving this setting at the default (auto) allows the switch to calculate the path-cost from the link speed.
Enable spanning tree operation on the switch with the
spanning-treecommand.