Got it

VBST Use Precautions

Latest reply: Jan 14, 2017 10:04:17 1888 1 0 0 0
  • When VBST is enabled on a ring network, VBST immediately starts spanning tree calculation. Parameters such as the device priority and port priority affect spanning tree calculation, and the change of these parameters may cause network flapping. To ensure fast and stable spanning tree calculation, perform basic configurations on the switch and interfaces before enabling VBST.

  • If the protected instance has been configured in a SEP segment or ERPS ring but the mapping between protected instances and VLANs is not configured, VBST cannot be enabled.

  • VBST cannot be enabled in the ignored VLAN or control VLAN used by ERPS, RRPP, SEP, or Smart Link.

  • If 1:N (N>1) mapping between MSTIs and VLANs has been configured on the switch, delete the mapping before changing the STP working mode to VBST.
  • If the stp vpls-subinterface enable command has been configured on a switch, run the undo stp vpls-subinterface enable command on an interface before changing the STP working mode to VBST.
  • If the device has been configured as the root bridge or secondary root bridge, run the undo stp vlan { vlan-id1 [ to vlan-id2 ] } &<1-10> root command to disable the root bridge or secondary root bridge function and run the stp vlan { vlan-id1 [ to vlan-id2 ] } &<1-10> priority priority command to change the device priority.

  • When more than 128 MSTIs are dynamically specified, STP is disabled in a created VLAN in the configuration file, for example, stp vlan 100 disable.

  • To prevent frequent network flapping, ensure that the values of Hello time, Forward Delay, and Max Age conform to the following formulas:

    • 2 x (Forward Delay - 1.0 second) ≥ Max Age

    • Max Age ≥ 2 x (Hello Time 1.0 second)

  • After all ports are configured as edge ports and BPDU filter ports in the system view, none of ports on the switch send BPDUs or negotiate the VBST status with directly connected ports on the remote device. All ports are in forwarding state. This may cause loops on the network, leading to broadcast storms. Exercise caution when you configure a port as an edge port and BPDU filter port.

  • After a port is configured as an edge port and BPDU filter port in the interface view, the port does not process or send BPDUs. The port cannot negotiate the VBST status with the directly connected port on the peer device. Exercise caution when you configure a port as an edge port and BPDU filter port.

  • Root protection takes effect only on designated ports.

  • An alternate port is the backup of the root port. If a switch has an alternate port, configure loop protection on both the root port and alternate port.

  • x
  • convention:

Created Jan 14, 2017 10:04:17

View more
  • x
  • convention:


You need to log in to comment to the post Login | Register

Notice: To protect the legitimate rights and interests of you, the community, and third parties, do not release content that may bring legal risks to all parties, including but are not limited to the following:
  • Politically sensitive content
  • Content concerning pornography, gambling, and drug abuse
  • Content that may disclose or infringe upon others ' commercial secrets, intellectual properties, including trade marks, copyrights, and patents, and personal privacy
Do not share your account and password with others. All operations performed using your account will be regarded as your own actions and all consequences arising therefrom will be borne by you. For details, see " User Agreement."

My Followers

Login and enjoy all the member benefits


Are you sure to block this user?
Users on your blacklist cannot comment on your post,cannot mention you, cannot send you private messages.
Please bind your phone number to obtain invitation bonus.
Information Protection Guide
Thanks for using Huawei Enterprise Support Community! We will help you learn how we collect, use, store and share your personal information and the rights you have in accordance with Privacy Policy and User Agreement.