H3C Technologies H3C S12500-X Series Switches - Manual (Page 84)

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MSTP implementation on devices
MSTP is compatible with STP and RSTP. Devices that are running MSTP and that are used for spanning
tree calculation can identify STP and RSTP protocol packets.
In addition to basic MSTP functions, the following functions are provided for ease of management:
• Root bridge hold
• Root bridge backup
• Root guard
• BPDU guard
• Loop guard
• TC-BPDU guard
• Port role restriction
• TC-BPDU transmission restriction
• Support for hot swapping of interface cards and active/standby changeover.
Protocols and standards
MSTP is documented in the following protocols and standards:
• IEEE 802.1d, Media Access Control (MAC) Bridges
• IEEE 802.1w, Part 3: Media Access Control (MAC) Bridges—Amendment 2: Rapid Reconfiguration
• IEEE 802.1s, Virtual Bridged Local Area Networks—Amendment 3: Multiple Spanning Trees
• IEEE 802.1Q-REV/D1.3, Media Access Control (MAC) Bridges and Virtual Bridged Local Area
Networks —Clause 13: Spanning tree Protocols
Spanning tree configuration task lists
Before configuring a spanning tree, you must determine the spanning tree protocol to be used (STP, RSTP,
or MSTP) and plan the device roles (the root bridge or leaf node).
• When both TRILL and a spanning tree protocol are enabled on a port, TRILL processes the BPDUs
received on the port. To make sure the STP network can interoperate with the TRILL network, disable
the spanning tree protocol on TRILL ports. For more information about TRILL, see TRILL Configuration
Guide.
• The spanning tree feature is mutually exclusive with service loopback group.
• Configurations made in system view take effect globally. Configurations made in Ethernet interface
view or WLAN mesh interface view take effect on the interface only. Configurations made in Layer
2 aggregate interface view take effect only on the aggregate interface. Configurations made on an
aggregation member port can take effect only after the port is removed from the aggregation
group.
• After you enable a spanning tree protocol on a Layer 2 aggregate interface, the system performs
spanning tree calculation on the Layer 2 aggregate interface, but not on the aggregation member
ports. The spanning tree protocol enable state and forwarding state of each selected member port
is consistent with those of the corresponding Layer 2 aggregate interface.