7.8.1.0 - Force10 Networks

• Max-age is the length of time the bridge maintains configuration information before it refreshes that
information by recomputing the RST topology.
Note: Force10 Networks recommends that only experienced network administrators change the Rapid
Spanning Tree group parameters. Poorly planned modification of the RSTG parameters can negatively
impact network performance.
Table 66 displays the default values for RSTP.
Table 66 RSTP Default Values
RSTP
Parameter Default Value
Forward Delay 15 seconds
Hello Time 2 seconds
Max Age 20 seconds
Port Cost 100-Mb/s Ethernet interfaces 200000
1-Gigabit Ethernet interfaces 20000
10-Gigabit Ethernet interfaces 2000
Port Channel with 100 Mb/s Ethernet interfaces 180000
Port Channel with 1-Gigabit Ethernet interfaces 18000
Port Channel with 10-Gigabit Ethernet interfaces 1800
Port Priority 128
To change these parameters, use the following commands, on the root bridge:
Task Command Syntax Command Mode
Change the forward-delay parameter.
• Range: 4 to 30
• Default: 15 seconds
Change the hello-time parameter.
Note: With large configurations (especially those with more
ports) Force10 Networks recommends that you increase the
hello-time.
Range: 1 to 10
Default: 2 seconds
Change the max-age parameter.
Range: 6 to 40
Default: 20 seconds
forward-delay seconds PROTOCOL
SPANNING TREE
RSTP
hello-time seconds PROTOCOL
SPANNING TREE
RSTP
max-age seconds PROTOCOL
SPANNING TREE
RSTP
View the current values for global parameters using the show spanning-tree rstp command from EXEC
privilege mode. See Figure 455.
FTOS Configuration Guide, version 7.8.1.0 671