Dell C9000 Series Networking Configuration Manual page 710

The default is 15 seconds.
2 Change the hello-time parameter.
PROTOCOL MSTP mode
hello-time seconds
NOTE: With large configurations (especially those configurations with more ports) Dell Networking
recommends increasing the hello-time.
The range is from 1 to 10.
The default is 2 seconds.
3 Change the max-age parameter.
PROTOCOL MSTP mode
max-age seconds
The range is from 6 to 40.
The default is 20 seconds.
4 Change the max-hops parameter.
PROTOCOL MSTP mode
max-hops number
The range is from 1 to 40.
The default is 20.
Example of the forward-delay Parameter
To view the current values for MSTP parameters, use the show running-config spanning-tree mstp
command from EXEC privilege mode.
Dell(conf-mstp)#forward-delay 16
Dell(conf-mstp)#exit
Dell(conf)#do show running-config spanning-tree mstp
!
protocol spanning-tree mstp
no disable
name my-mstp-region
MSTI 1 VLAN 100
MSTI 2 VLAN 200-300
forward-delay 16
MSTI 2 bridge-priority 4096
Dell(conf)#
Multiple Spanning Tree Protocol (MSTP) 710