Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 658

• Assign a bridge priority. PROTOCOL PVST mode vlan bridge-priority The range is from 0 to 61440. The default is 32768. Example of the show spanning-tree pvst vlan Command To display the PVST+ forwarding topology, use the show spanning-tree pvst [vlan vlan-id] command from EXEC Privilege mode. Dell(conf)#do show spanning-tree pvst vlan 100 VLAN 100 Root Identifier has priority 4096, Address 0001.e80d.b6d6 Root Bridge hello time 2, max age 20, forward delay 15 Bridge Identifier has priority 4096, Address 0001.e80d.b6d6 Configured hello time 2, max age 20, forward delay 15 We are the root of VLAN 100 Current root has priority 4096, Address 0001.e80d.b6d6 Number of topology changes 5, last change occurred 00:34:37 ago on Te 1/32 Port 375 (TengigabitEthernet 1/22) is designated Forwarding Port path cost 20000, Port priority 128, Port Identifier 128.375 Designated root has priority 4096, address 0001.e80d.b6:d6 Designated bridge has priority 4096, address 0001.e80d.b6:d6 Designated port id is 128.375 , designated path cost 0 Number of transitions to forwarding state 2 BPDU sent 1159, received 632 The port is not in the Edge port mode Port 385 (TengigabitEthernet 1/32) is designated Forwarding Port path cost 20000, Port priority 128, Port Identifier 128.385 Designated root has priority 4096, address 0001.e80d.b6:d6 Designated bridge has priority 4096, address 0001.e80d.b6:d6 Designated port id is 128.385 , designated path cost 0 Modifying Global PVST+ Parameters The root bridge sets the values for forward-delay and hello-time, and overwrites the values set on other PVST+ bridges. • 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 bridge protocol data units (BPDUs). • Max-age - the length of time the bridge maintains configuration information before it refreshes that information by recomputing the PVST+ topology. To change PVST+ parameters on the root bridge, use the following commands. • Change the forward-delay parameter. PROTOCOL PVST mode vlan forward-delay The range is from 4 to 30. The default is 15 seconds. • Change the hello-time parameter. PROTOCOL PVST mode vlan hello-time Per-VLAN Spanning Tree Plus (PVST+) 658