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NOTE: With large configurations (especially those configurations with more ports) Dell Networking recommends
increasing the hello-time.
The range is from 1 to 10.
The default is 2 seconds.
● Change the max-age parameter.
PROTOCOL SPANNING TREE RSTP mode
max-age seconds
The range is from 6 to 40.
The default is 20 seconds.
To view the current values for global parameters, use the show spanning-tree rstp command from EXEC privilege mode.
Modifying Interface Parameters
On interfaces in Layer 2 mode, you can set the port cost and port priority values.
● Port cost — a value that is based on the interface type. The previous table lists the default values. The greater the port
cost, the less likely the port is selected to be a forwarding port.
● Port priority — influences the likelihood that a port is selected to be a forwarding port in case that several ports have the
same port cost.
To change the port cost or priority of an interface, use the following commands.
● Change the port cost of an interface.
INTERFACE mode
spanning-tree rstp cost cost
The range is from 0 to 65535.
The default is listed in the previous table.
● Change the port priority of an interface.
INTERFACE mode
spanning-tree rstp priority priority-value
The range is from 0 to 15.
The default is 128.
To view the current values for interface parameters, use the show spanning-tree rstp command from EXEC privilege
mode.
Configuring an EdgePort
The EdgePort feature enables interfaces to begin forwarding traffic approximately 30 seconds sooner.
In this mode an interface forwards frames by default until it receives a BPDU that indicates that it should behave otherwise;
it does not go through the Learning and Listening states. The bpduguard shutdown-on-violation option causes the
interface hardware to shut down when it receives a BPDU. When only bpduguard is implemented, although the interface is
placed in an Error Disabled state when receiving the BPDU, the physical interface remains up and spanning-tree drops packets
in the hardware after a BPDU violation. BPDUs are dropped in the software after receiving the BPDU violation. This feature is
the same as PortFast mode in Spanning Tree.
CAUTION:
Configure EdgePort only on links connecting to an end station. If you enable EdgePort on an interface
connected to a network, it can cause loops.
Dell Networking OS Behavior: Regarding bpduguard shutdown-on-violation behavior:
● If the interface to shut down is a port channel, all the member ports are disabled in the hardware.
● When you add a physical port to a port channel already in the Error Disable state, the new member port is also disabled in the
hardware.
● When you remove a physical port from a port channel in the Error Disable state, the error disabled state is cleared on this
physical port (the physical port is enabled in the hardware).
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Rapid Spanning Tree Protocol (RSTP)