Users Guide

Table Of Contents
96 Switch Feature Overview
Bridge Protocol Data Unit (BPDU) Guard
Spanning Tree BPDU Guard is used to disable the port in case a new device
tries to enter the already existing topology of STP. Thus devices, which were
originally not a part of STP, are not allowed to influence the STP topology.
BPDU Filtering
When spanning tree is disabled on a port, the BPDU Filtering feature allows
BPDU packets received on that port to be dropped. Additionally, the BPDU
Filtering feature prevents a port in Port Fast mode from sending and receiving
BPDUs. A port in Port Fast mode is automatically placed in the forwarding
state when the link is up to increase convergence time.
RSTP-PV and STP-PV
Dell EMC Networking N-Series switches support both Rapid Spanning Tree
Per VLAN (RSTP-PV) and Spanning Tree Per VLAN (STP-PV). RSTP-PV is
the IEEE 802.1w (RSTP) standard implemented per VLAN. A single instance
of rapid spanning tree (RSTP) runs on each configured VLAN. Each RSTP
instance on a VLAN has a root switch. STP-PV is the IEEE 802.1s (STP)
standard implemented per VLAN.