Quanta Cloud Technology QuantaMesh QNOS5, Configuration Manual

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To further illustrate the full connectivity in an MSTP active topology, the following rules apply:
1. Each Bridge or LAN is in only one Region.
2. Every frame is associated with only one VID.
3. Frames are allocated either to the IST or MSTI within any given Region.
4. The internal spanning tree (IST) and each MSTI provides full and simple connectivity between all LANs and
Bridges in a Region.
5. All Bridges within a Region reach a consistent agreement as to which ports interconnect that Region to a
different Region and label those as Boundary Ports.
6. At the Boundary Ports, frames allocated to the CIST or MSTIs are forwarded or not forwarded alike.
7. The CIST provides full and simple connectivity between all LANs and Bridges in the network.
3.8.4. Optional STP Features
QNOS software supports the following optional STP features:
• BPDU flooding
• Edge Port
• BPDU filtering
• Root guard
• Loop guard
• BPDU protection
3.8.4.1. BPDU Flooding
The BPDU flooding feature determines the behavior of the switch when it receives a BPDU on a port that is
disabled for spanning tree. If BPDU flooding is configured, the switch will flood the received BPDU to all the
ports on the switch which are similarly disabled for spanning tree.
3.8.4.2. Edge Port
The Edge Port feature reduces the STP convergence time by allowing ports that are connected to end devices
(such as a desktop computer, printer, or file server) to transition to the forwarding state without going
through the listening and learning states.
3.8.4.3. PDU Filtering