Dell Force10 S4820T S4820T Configuration Guide - Page 811

Figure 41-6. show spanning-tree rstp brief Command Example R3#show spanning-tree rstp brief Executing IEEE compatible Spanning Tree Protocol Root ID Priority 32768, Address 0001.e801.cbb4 Root Bridge hello time 2, max age 20, forward delay 15 Bridge ID Priority 32768, Address 0001.e80f.1dad Configured hello time 2, max age 20, forward delay 15 Interface Designated Name PortID Prio Cost Sts Cost Bridge ID PortID Gi 3/1 128.681 128 20000 BLK 20000 32768 0001.e80b.88bd 128.469 Gi 3/2 128.682 128 20000 BLK 20000 32768 0001.e80b.88bd 128.470 Gi 3/3 128.683 128 20000 FWD 20000 32768 0001.e801.cbb4 128.379 Gi 3/4 128.684 128 20000 BLK 20000 32768 0001.e801.cbb4 128.380 Interface Name Role PortID Prio Cost Sts Cost Link-type Edge Gi 3/1 Altr 128.681 128 20000 BLK 20000 P2P No Gi 3/2 Altr 128.682 128 20000 BLK 20000 P2P No Gi 3/3 Root 128.683 128 20000 FWD 20000 P2P No Gi 3/4 Altr 128.684 128 20000 BLK 20000 P2P No R3# Add and Remove Interfaces • To add an interface to the Rapid Spanning Tree topology, configure it for Layer 2 and it is automatically added. If you previously disabled RSTP on the interface using the command no spanning-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 950 for BPDU Filtering behavior. Modify Global Parameters You 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 Spanning Tree group. • Forward-delay is the amount of time an interface waits in the Listening State and the Learning State before 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 that information by recomputing the RST topology. Note: Dell Force10 recommends that only experienced network administrators change the Rapid Spanning Tree group parameters. Poorly planned modification of the RSTG parameters can negatively impact network performance. Rapid Spanning Tree Protocol (RSTP) | 811