Modifying Global Parameters - Dell Force10 MXL Blade Configuration Manual

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.
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
Forward Delay
Hello Time
Max Age
Port Cost 40-Gigabit Ethernet interfaces
10-Gigabit Ethernet interfaces
Port Channel with 40-Gigabit Ethernet interfaces
Port Channel with 10-Gigabit Ethernet interfaces
Port Priority
To change the STP global parameters, use the following commands:
Task
Change the forward-delay parameter (the wait time before the
interface enters the Forwarding state).
• Range: 4 to 30
• Default: 15 seconds
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
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
To view the current values for global parameters, use the
privilege mode (Figure 33-5).
Default Value
15 seconds
2 seconds
20 seconds
1
2
1
1
8
Command Syntax
forward-delay seconds
hello-time seconds
max-age seconds
command from EXEC
show spanning-tree 0
Spanning Tree Protocol (STP) | 583
Command Mode
PROTOCOL
SPANNING TREE
PROTOCOL
SPANNING TREE
PROTOCOL
SPANNING TREE