Rapid Spanning Tree Protocol (RSTP) | 775Figure 38-6. show spanning-tree rstp brief Command ExampleAdd and Remove Interfaces• To add an interface to the Rapid Spanning Tree topology, configure it for Layer 2 and it isautomatically added. If you previously disabled RSTP on the interface using the command nospanning-tree 0, re-enable it using the command spanning-tree 0.• Remove an interface from the Rapid Spanning Tree topology using the command no spanning-tree 0.See also Removing an Interface from the Spanning Tree Group on page 880 for BPDU Filteringbehavior.Modify Global ParametersYou can modify Rapid 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 the Rapid SpanningTree group.• Forward-delay is the amount of time an interface waits in the Listening State and the Learning Statebefore it transitions to the Forwarding State.• Hello-time is the time interval in which the bridge sends RSTP Bridge Protocol Data Units (BPDUs).• Max-age is the length of time the bridge maintains configuration information before it refreshes thatinformation by recomputing the RST topology.Note: Dell Force10 recommends that only experienced network administrators change the Rapid SpanningTree group parameters. Poorly planned modification of the RSTG parameters can negatively impactnetwork performance.R3#show spanning-tree rstp briefExecuting IEEE compatible Spanning Tree ProtocolRoot ID Priority 32768, Address 0001.e801.cbb4Root Bridge hello time 2, max age 20, forward delay 15Bridge ID Priority 32768, Address 0001.e80f.1dadConfigured hello time 2, max age 20, forward delay 15Interface DesignatedName PortID Prio Cost Sts Cost Bridge ID PortID---------- -------- ---- ------- --- ------- -------------------- --------Gi 3/1 128.681 128 20000 BLK 20000 32768 0001.e80b.88bd 128.469Gi 3/2 128.682 128 20000 BLK 20000 32768 0001.e80b.88bd 128.470Gi 3/3 128.683 128 20000 FWD 20000 32768 0001.e801.cbb4 128.379Gi 3/4 128.684 128 20000 BLK 20000 32768 0001.e801.cbb4 128.380InterfaceName Role PortID Prio Cost Sts Cost Link-type Edge---------- ------ -------- ---- ------- --- ------- --------- ----Gi 3/1 Altr 128.681 128 20000 BLK 20000 P2P NoGi 3/2 Altr 128.682 128 20000 BLK 20000 P2P NoGi 3/3 Root 128.683 128 20000 FWD 20000 P2P NoGi 3/4 Altr 128.684 128 20000 BLK 20000 P2P NoR3#
