Dell Force10 MXL Blade - Modifying Global Parameters

Spanning Tree Protocol (STP) | 583
Modifying Global Parameters
You can modify the STP parameters. The root bridge sets the values for forward-delay, hello-time, and
max-age and overwrites the values set on other bridges participating in STP.
To change the STP global parameters, use the following commands:
To view the current values for global parameters, use the
show spanning-tree 0 command from EXEC
privilege mode (Figure 33-5).
Note: Dell Force10 recommends that only experienced network administrators change the STP
parameters. Poorly planned modification of the STP parameters can negatively impact network
performance.
Table 33-2. Default Values for STP
STP Parameter Default Value
Forward Delay 15 seconds
Hello Time 2 seconds
Max Age 20 seconds
Port Cost 40-Gigabit Ethernet interfaces 1
10-Gigabit Ethernet interfaces 2
Port Channel with 40-Gigabit Ethernet interfaces 1
Port Channel with 10-Gigabit Ethernet interfaces 1
Port Priority 8
Task Command Syntax Command Mode
Change the forward-delay parameter (the wait time before the
interface enters the Forwarding state).
• Range: 4 to 30
• Default: 15 seconds
forward-delay seconds PROTOCOL
SPANNING TREE
Change the hello-time parameter (the BPDU transmission interval).
Note: With large configurations (especially those with more ports) Dell
Force10 recommends increasing the hello-time.
Range: 1 to 10
Default: 2 seconds
hello-time seconds PROTOCOL
SPANNING TREE
Change the max-age parameter (the refresh interval for configuration
information that is generated by recomputing the STP topology).
Range: 6 to 40
Default: 20 seconds
max-age seconds PROTOCOL
SPANNING TREE