spanning-tree mode mst

The default configuration of the spanning-tree protocol (STP) on a Catalyst 2960 Series switch is PVST+. A Catalyst 2960 series switches support PVST+, Rapid PVST+, and MST, but at the time only one version can be active for all VLANs. Rapid PVST+ is the Cisco execution of RSTP supporting RSTP on a per-VLAN basis.

We can control the configuration of the VLAN spanning-tree instance using the Rapid PVST+ commands. A spanning-tree instance is created while an interface is assigned to a VLAN.

When all the interfaces are removed from the VLAN or moved to any other VLAN then the instance is removed. The STP switches and port parameters can be configured before a spanning-tree instance is created. These configured parameters are applied when a spanning tree instance is created.

Spanning-Tree Mode Configuration

The command for configuring the Rapid PVST+ on a Cisco switch is “spanning-tree mode rapid-pvst” The command can be used in global configuration mode. We can use the same command to change the spanning-tree mode i.e PVST, MST etc.

We can The show spanning-tree vlan <vlan_number> command to shows the spanning tree configuration for a specific VLAN. We can also use the show running-config command to verify the Rapid PVST+ configuration.

The point-to-point link-type parameter for Rapid PVST+ is not necessary because it is abnormal to have a shared link-type. Mostly the difference between configuring PVST+ and Rapid PVST+ is the spanning-tree mode rapid-pvst command. The command for the link-type parameter is “spanning-tree link-type point-to-point”