Modifying The Interface Parameters - Dell S3048-ON Configuration Manual

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)#

Modifying the Interface Parameters

You can adjust two interface parameters to increase or decrease the probability that a port becomes a forwarding port.
• Port cost is a value that is based on the interface type. The greater the port cost, the less likely the port is selected to be a forwarding
port.
• Port priority influences the likelihood that a port is selected to be a forwarding port in case that several ports have the same port cost.
The following lists the default values for port cost by interface.
Table 43. Default Values for Port Costs by Interface
Port Cost
100-Mb/s Ethernet interfaces
1-Gigabit Ethernet interfaces
10-Gigabit Ethernet interfaces
Default Value
200000
20000
2000
Multiple Spanning Tree Protocol (MSTP) 503