Cisco SG200 Series Administration Manual page 122

Spanning Tree
Configuring STP Interface Settings
STEP 4
Cisco Small Business SG200 Series 8-port Smart Switch
• STP—Select to enable STP operation on the port/LAG.
• Auto Edge—Select Enable to allow the switch to automatically determine if
the port is an edge port or PortFast. A port is an edge port if it is not
connected to a bridge. Auto-detection speeds up the transition of the port to
forwarding state. A port can forward traffic and learn MAC addresses when
it is in forwarding state.
• Edge Port—Select Enable to manually configure the port as an edge port.
• BPDU Handling—Bridge Protocol Data Units (BPDUs) are the messages
exchanged between switches to calculate STP topology. Select the method
of BPDU packet handling when the spanning tree is disabled on an interface:
- Filtering—Enables the port to discard BPDUs received on interfaces
that are not enabled for STP.
- Flooding—Allows flooding of BPDUs received on non-spanning-tree
ports to all other non-spanning-tree ports.
• Path Cost—Specify the port path cost. The cost of a path to the root bridge
is the sum of the costs of all ports in the path. The path cost is used by CST
and RSTP to forward traffic when a path is being rerouted. Select Use
Default to set the path cost to the port speed. Or select User Defined to set
a custom value between 0 and 200,000,000. A value of zero means the path
cost is set according to the port's speed.
Click Apply and then click Close. Your changes are saved to the Running
Configuration.
The new configuration appears in the STP Interface Settings Table along with the
following information about the port/LAG.
• Operational Edge Status—Indicates if a port is currently operating as an
edge port (or PortFast port). This will indicate Enabled if the port is in the
forwarding state due to either of the following configurations:
- The port is configured as an Edge Port and is therefore automatically in
the forwarding state.
- The port is configured as an Auto Edge port and, because it has not
received BDPUs, has transitioned to forwarding state.
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