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8.3 Statistics
Click
STP
>
Statistics
To display STP statistics
Bridge Protocol Data Units
(BPDUs) are frames that contain information about the
Spanning
tree protocol
(STP). Switches send BPDUs using a unique
MAC address
from its origin port and a
multicast address as destination MAC (01:80:C2:00:00:00, or 01:00:0C:CC:CC:CD for
Per VLAN
Spanning Tree
). For STP algorithms to function, the switches need to share information about
themselves and their connections. What they share are bridge protocol data units (BPDUs). BPDUs
are sent out as multicast frames to which only other layer 2 switches or bridges are listening. If any
loops (multiple possible paths between switches) are found in the network topology, the switches
will co-operate to disable a port or ports to ensure that there are no loops; that is, from one device
to any other device in the layer 2 network, only one path can be taken.
