Enabling VBST
Context
The VBST configuration takes effect only when VBST is enabled.
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.
The PV quantity is the number of VBST-enabled interfaces multiplied by the number of VLANs. If the PV quantity exceeds the specifications, the CPU usage may exceed the threshold. As a result, the switch cannot process tasks in a timely manner, protocol calculation is affected, and even the device cannot be managed by the NMS. The PV quantity supported by the device is as follows:
The CPU usage of VBST is in direct proportion to the PV quantity.
EE series, and X series cards, ET1D2L02QSC0, ET1D2L08QSC0, and ET1D2X48SEC0 cards support up to 1200 PVs, and other cards support up to 300 PVs.
The number of PVs supported by the switch is the total number of PVs supported by running cards of the switch.
For the Eth-Trunk, the device supports up to 1000 PVs.
Procedure
- Run:
system-viewThe system view is displayed.
- Run:
stp mode vbst
The working mode of the switch is set to VBST.
By default, the switch works in MSTP mode.
The VBST mode cannot be used with the STP/RSTP/MSTP mode.
If a protected instance in a segment has been configured by the protected-instance (sep segment view) command or a protected instance in an ERPS ring has been configured by the protected-instance (ERPS ring view) command, you must perform the operation of (Optional) Manually Configuring the Mapping between MSTIs and VLANs. Otherwise, the STP working mode cannot be changed to VBST.
- If 1:N (N>1) mapping between MSTIs and VLANs has been configured on the switch, the mapping must be deleted before changing the STP working mode to VBST.
- If stp vpls-subinterface enable has been configured on the switch, the undo stp vpls-subinterface enable command must be run on the interface before changing the STP working mode to VBST.
- Run:
stp enableGlobal STP is enabled.
By default, STP is enabled globally.
- Run:
stp vlan { vlan-id1 [ to vlan-id2 ] } &<1-10> enable
VBST is enabled in each VLAN.
By default, VBST is enabled in a 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.
- Run:
interface interface-type interface-number
The interface view is displayed.
- Run:
stp enableSTP is enabled on the interface.
By default, STP is enabled on each switch interface.
STP cannot be used with SEP or Smart Link. An STP-enabled interface cannot join a SEP segment or Smart Link group. Similarly, the interface that has joined the SEP segment or Smart Link group cannot be enabled with STP.
