spanning-tree 0Modifying Global ParametersYou can modify the 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 STP.NOTE: Dell Networking recommends that only experienced network administrators change thespanning tree parameters. Poorly planned modification of the spanning tree parameters cannegatively affect network performance.The following table displays the default values for STP.Table 90. STP Default ValuesSTP Parameters Default ValueForward Delay 15 secondsHello Time 2 secondsMax Age 20 secondsPort Cost• 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 Ethernetinterfaces• 19• 4• 2• 18• 3• 1Port Priority 8• Change the forward-delay parameter (the wait time before the interface enters the Forwardingstate).PROTOCOL SPANNING TREE modeforward-delay secondsThe range is from 4 to 30.The default is 15 seconds.• Change the hello-time parameter (the BPDU transmission interval).PROTOCOL SPANNING TREE modehello-time secondsNOTE: With large configurations (especially those with more ports) Dell Networkingrecommends increasing the hello-time.The range is from 1 to 10.the default is 2 seconds.• Change the max-age parameter (the refresh interval for configuration information that is generatedby recomputing the spanning tree topology).872 Spanning Tree Protocol (STP)
