The range is from 0 to 15.The default is 8.To view the current values for interface parameters, use the show spanning-tree 0 command from EXECprivilege mode. Refer to the second example in Enabling Spanning Tree Protocol Globally.Enabling PortFastThe PortFast feature enables interfaces to begin forwarding traffic approximately 30 seconds sooner.Interfaces forward frames by default until they receive a BPDU that indicates that they should behaveotherwise; they do not go through the Learning and Listening states. The bpduguard shutdown-on-violation option causes the interface hardware to be shut down when it receives a BPDU. When you onlyimplement bpduguard, although the interface is placed in an Error Disabled state when receiving the BPDU,the physical interface remains up and spanning-tree drops packets in the hardware after a BPDU violation.BPDUs are dropped in the software after receiving the BPDU violation.CAUTION: Enable PortFast only on links connecting to an end station. PortFast can cause loops if it isenabled on an interface connected to a network.To enable PortFast on an interface, use the following command.• Enable PortFast on an interface.INTERFACE modespanning-tree stp-id portfast [bpduguard | [shutdown-on-violation]]Example of Verifying PortFast is Enabled on an InterfaceTo verify that PortFast is enabled on a port, use the show spanning-tree command from EXEC Privilegemode or the show config command from INTERFACE mode. Dell Networking recommends using the showconfig command.Dell#(conf-if-te-1/1)#show conf!interface TenGigabitEthernet 1/1no ip addressswitchportspanning-tree 0 portfastno shutdownDell#(conf-if-te-1/1)#Spanning Tree Protocol (STP) 1082
