User manual

S PANNING T REE A LGORITHM C ONFIGURATION
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• Multiple Spanning Tree Protocol
- To allow multiple spanning trees to operate over the network, you
must configure a related set of bridges with the same MSTP
configuration, allowing them to participate in a specific set of
spanning tree instances.
- A spanning tree instance can exist only on bridges that have
compatible VLAN instance assignments.
- Be careful when switching between spanning tree modes. Changing
modes stops all spanning-tree instances for the previous mode and
restarts the system in the new mode, temporarily disrupting user
traffic.
Command Attributes
Basic Configuration of Global Settings
• Spanning Tree State – Enables/disables STA on this switch.
(Default: Enabled)
• Spanning Tree Type – Specifies the type of spanning tree used on
this switch:
- STA: Spanning Tree Algorithm (IEEE 802.1D); i.e., when this
option is selected, the switch will use RSTP set to STA forced
compatibility mode).
- RSTP: Rapid Spanning Tree (IEEE 802.1w); RSTP is the default.
- MSTP: Multiple Spanning Tree (IEEE 802.1s)
• Priority – Bridge priority is used in selecting the root device, root port,
and designated port. The device with the highest priority becomes the
STA root device. However, if all devices have the same priority, the
device with the lowest MAC address will then become the root device.
(Note that lower numeric values indicate higher priority.)
- Default: 32768
- Range: 0-61440, in steps of 4096
- Options: 0, 4096, 8192, 12288, 16384, 20480, 24576, 28672, 32768,
36864, 40960, 45056, 49152, 53248, 57344, 61440