Dell PowerSwitch S4820T Configuration Guide for the S4820T System 9.112.0P1 - Page 758

Designated bridge has priority 32768, address 0001.e801.cbb4 Designated port id is 128.379, designated path cost 0 Number of transitions to forwarding state 1 BPDU : sent 121, received 5 The port is not in the Edge port mode Port 380 (TenGigabitEthernet 2/4) is designated Forwarding Port path cost 20000, Port priority 128, Port Identifier 128.380 Designated root has priority 32768, address 0001.e801.cbb4 Designated bridge has priority 32768, address 0001.e801.cbb4 Designated port id is 128.380, designated path cost 0 Number of transitions to forwarding state 1 BPDU : sent 147, received 3 The port is not in the Edge port mode To confirm that a port is participating in RSTP, use the show spanning-tree rstp brief command from EXEC privilege mode. 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 Te 3/1 128.681 128 20000 BLK 20000 32768 0001.e80b.88bd 128.469 Te 3/2 128.682 128 20000 BLK 20000 32768 0001.e80b.88bd 128.470 Te 3/3 128.683 128 20000 FWD 20000 32768 0001.e801.cbb4 128.379 Te 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 Te 3/1 Altr 128.681 128 20000 BLK 20000 P2P No Te 3/2 Altr 128.682 128 20000 BLK 20000 P2P No Te 3/3 Root 128.683 128 20000 FWD 20000 P2P No Te 3/4 Altr 128.684 128 20000 BLK 20000 P2P No R3# Adding and Removing Interfaces To 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 previously disabled RSTP on the interface using the command no spanning-tree 0 command, re-enable it using the spanning-tree 0 command. • Remove an interface from the Rapid Spanning Tree topology. no spanning-tree 0 Modifying Global Parameters You 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 bridges participating 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 the Forwarding 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 by recomputing the RST topology. NOTE: Dell Networking recommends that only experienced network administrators change the Rapid Spanning Tree group parameters. Poorly planned modification of the RSTP parameters can negatively affect network performance. 758 Rapid Spanning Tree Protocol (RSTP)