Dell PowerSwitch S4820T Configuration Guide for the S4820T System 9.112.0P1 - Page 570

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 61. 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 570 Multiple Spanning Tree Protocol (MSTP)