Modifying Global Parameters - Dell Force10 Z9000 Configuration Manual

Modifying Global Parameters

You can modify Spanning Tree 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 Spanning Tree.
Note: Dell Force10 recommends that only experienced network administrators change the Spanning Tree
parameters. Poorly planned modification of the Spanning Tree parameters can negatively impact network
performance.
Table 44-2 displays the default values for Spanning Tree.
Table 44-2. STP Default Values
STP Parameter
Forward Delay
Hello Time
Max Age
Port Cost
Port Priority
To change STP global parameters:
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 that you increase 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 Spanning Tree
topology).
Range: 6 to 40
Default: 20 seconds
100-Mb/s Ethernet interfaces
1-Gigabit Ethernet interfaces
10-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
Default Value
15 seconds
2 seconds
20 seconds
19
4
2
18
3
1
8
Command Syntax
forward-delay seconds
hello-time seconds
max-age seconds
Spanning Tree Protocol (STP) | 881
Command Mode
PROTOCOL
SPANNING TREE
PROTOCOL
SPANNING TREE
PROTOCOL
SPANNING TREE