The stp vlan enable command enables VBST in a VLAN on the switch.
The stp vlan disable command disables VBST in a VLAN on the switch.
The undo stp vlan disable command restores the default VBST status in a VLAN on the switch.By default, VBST is enabled in a VLAN on the switch.
stp vlan { vlan-id1 [ to vlan-id2 ] } &<1-10> enable
stp vlan { vlan-id1 [ to vlan-id2 ] } &<1-10> disable
undo stp vlan { vlan-id1 [ to vlan-id2 ] } &<1-10> disable
| Parameter | Description | Value |
|---|---|---|
| vlan vlan-id1 [ to vlan-id2 ] | Specifies one or more VLANs in which VBST is enabled.
In the stp enable command, you can specify a maximum of 10 VLAN ranges. |
The value is an integer that ranges from 1 to 4094. |
Usage Scenario
On a complex Layer 2 network, to prevent or eliminate loops and allow traffic in different VLANs to be forwarded along spanning trees to implement load balancing, deploy VBST on the switch.
Spanning tree calculation occupies system resources. Therefore, run the stp vlan disable command to disable VBST in a VLAN where spanning tree calculation does not need to be performed.
Pre-configuration Tasks
When VBST is enabled on a ring network, VBST immediately starts spanning tree calculation. Parameters such as the switch priority and port priority affect spanning tree calculation, and change of these parameters may cause network flapping. To ensure fast and stable spanning tree calculation, perform basic configurations on the switch and ports before enabling VBST.Run the stp mode vbst command to set the working mode of the switch.
Run the stp vlan { vlan-id1 [ to vlan-id2 ] } &<1-10> priority priority command to set the priority of the switch in the spanning tree.
Run the stp vlan { vlan-id1 [ to vlan-id2 ] } &<1-10> port priority priority command to set the priority of the port in the spanning tree instance.
Run the stp vlan { vlan-id1 [ to vlan-id2 ] } &<1-10> root primary command to set the switch as the root bridge of the spanning tree instance.
Run the stp vlan { vlan-id1 [ to vlan-id2 ] } &<1-10> root secondary command to set the switch as the secondary root bridge of the spanning tree.
Run the stp vlan { vlan-id1 [ to vlan-id2 ] } &<1-10> costcost command to set the path cost of the port in the spanning tree instance.
Run the instance instance-id vlan vlan-id command to configure 1:1 mapping between MSTIs and VLANs.
Configurations are needed based on real-world situations.
Precautions
When VBST is enabled globally and in a VLAN, the interface that belongs to the VLAN participates in spanning tree calculation. Whether the interface is in forwarding state depends on the calculation result.
When VBST is disabled in a VLAN, the interface that belongs to the VLAN does not participate in spanning tree calculation and is in forwarding state in the VLAN.
VBST cannot be enabled in the ignored VLAN or control VLAN used by ERPS, RRPP, SEP, or Smart Link.
If VLAN mapping or VLAN stacking is configured on an interface corresponding to the VLAN, VBST negotiation for this VLAN will fail.