Adding and Removing InterfacesTo add and remove interfaces, use the following commands.To add an interface to the Rapid Spanning Tree topology, configure it for Layer 2 and it is automatically added. If you previouslydisabled RSTP on the interface using the command no spanning-tree 0 command, re-enable it using the spanning-tree0 command.• Remove an interface from the Rapid Spanning Tree topology.no spanning-tree 0Modifying Global ParametersYou can modify RSTP parameters.The root bridge sets the values for forward-delay, hello-time, and max-age and overwrites the values set on other bridgesparticipating in the Rapid Spanning Tree group.• Forward-delay — the amount of time an interface waits in the Listening state and the Learning state before it transitions to theForwarding state.• Hello-time — the time interval in which the bridge sends RSTP BPDUs.• Max-age — the length of time the bridge maintains configuration information before it refreshes that information byrecomputing the RST topology.NOTE: Dell Networking recommends that only experienced network administrators change the Rapid Spanning Treegroup parameters. Poorly planned modification of the RSTP parameters can negatively affect network performance.The following table displays the default values for RSTP.Table 79. RSTP Default ValuesRSTP Parameter 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 Ethernet interfacesPort Cost:• 200000• 20000• 2000• 180000• 18000• 1800Port Priority 128To change these parameters, use the following commands.• Change the forward-delay parameter.PROTOCOL SPANNING TREE RSTP modeforward-delay secondsThe range is from 4 to 30.The default is 15 seconds.• Change the hello-time parameter.730 Rapid Spanning Tree Protocol (RSTP)
