Allied Telesis AT-GS950/48, User Manual

Page: 92 / 410

Chapter 5: Multiple Spanning Tree Protocol
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Blocking - A blocking state does not allow network traffic to be
sent or received on a the port, except for BPDU data. A port with
a higher path cost to the root bridge than another on the switch
will cause a switching loop and is placed in the blocking state by
the Spanning Tree algorithm. The port’s state may change to
the forwarding state if the other links in use fail, and the
Spanning Tree algorithm determines the port may transition to
the forwarding state.
Listening - This state occurs on a port during the convergence
process. The port in the listening state processes BPDUs and
awaits new information that would cause the port to return to the
blocking state.
Learning - While the port does not yet forward frames (packets)
in this state, the port does learn source addresses from frames
received and adds them to the filtering (switching) database.
Forwarding - A port that both receives and sends data. This
indicates normal operation. STP continues to monitor the port
for incoming BPDUs that indicate the port should return to the
blocking state to prevent a loop.
Disabled - This state is not strictly part of STP. However, a
network administrator can manually disable a port.
Edge - Specifies whether or not a port is connected to an edge
device in the network topology. See “Point-to-Point and Edge
Ports” on page 76 for more information.
Auto - The switch will automatically determine the port type.
ForceTrue - The port is connected to an edge device, and the
port will always be in a forwarding state.
ForceFalse - The port is not connected to an edge device.
P2P - Specifies if the port is connected to another network device
(point-to-point) in the network topology. See “Point-to-Point and
Edge Ports” on page 76 for more information.
Auto - The switch will automatically determine the port type.
ForceTrue - The port is connected to a network device in the
network topology.
ForceFalse - The port is not connected to a network device in
the network topology.
Restricted Role - This parameter prevents the port from becoming
a root port.
True - The port is prevented from being a root port or a port that
is used to communicate with the root bridge.