Users Guide

Table 92. STP Default Values (continued)
STP Parameters Default Value
• 100-Mb/s Ethernet interfaces
• 1-Gigabit Ethernet interfaces
• 10-Gigabit Ethernet interfaces
• 40-Gigabit Ethernet interfaces
• Port Channel with 100 Mb/s Ethernet interfaces
• Port Channel with 1-Gigabit Ethernet interfaces
• Port Channel with 10-Gigabit Ethernet interfaces
• Port Channel with 40-Gigabit Ethernet interfaces
• 20000
• 2000
• 1400
• 180000
• 18000
• 1800
• 600
Port Priority 8
• Change the forward-delay parameter (the wait time before the interface enters the Forwarding state).
PROTOCOL SPANNING TREE mode
forward-delay seconds
The range is from 4 to 30.
The default is 15 seconds.
• Change the hello-time parameter (the BPDU transmission interval).
PROTOCOL SPANNING TREE mode
hello-time seconds
NOTE:
With large configurations (especially those 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 (the refresh interval for configuration information that is generated by recomputing the spanning
tree topology).
PROTOCOL SPANNING TREE 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 0 command from EXEC privilege mode. Refer to the
second example in Enabling Spanning Tree Protocol Globally.
Modifying Interface STP Parameters
You can set the port cost and port priority values of interfaces in Layer 2 mode.
• Port cost — a value that is based on the interface type. 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.
The default values are listed in Modifying Global Parameters.
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 0 cost cost
The range is from 0 to 65535.
The default values are listed in Modifying Global Parameters.
• Change the port priority of an interface.
INTERFACE mode
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Spanning Tree Protocol (STP)