Dell POWEREDGE M1000E - Manual (Page 26)

24 Introduction
Spanning Tree Root Guard
Spanning Tree Root Guard is used to prevent the root of a Spanning Tree instance from changing
unexpectedly. The priority of a Bridge ID can be set to zero but another Bridge ID with a lower mac
address could also set its priority to zero and take over root.
Bridge Protocol Data Unit 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.
Link Aggregation Features
Link Aggregation
Up to eight ports can combine to form a single Link Aggregated Group (LAG). This enables fault
tolerance protection from physical link disruption, higher bandwidth connections and improved
bandwidth granularity.
A LAG is composed of ports of the same speed, set to full-duplex operation.
For information about configuring LAGs, see "LAG Configuration."
Link Aggregation and LACP
Link Aggregate Control Protocol (LACP) uses peer exchanges across links to determine, on an ongoing
basis, the aggregation capability of various links, and continuously provides the maximum level of
aggregation capability achievable between a given pair of systems. LACP automatically determines,
configures, binds, and monitors the binding of ports to aggregators within the system.
For information about LACP, see "LACP Parameters."