Connectivity Guide

Enable RPVST+
By default, RPVST+ is enabled and creates an instance only after you add the rst member port to a VLAN. To participate in RPVST+, port-
channel or physical interfaces must be a member of a VLAN. Add all physical and port-channel interfaces to the default VLAN (VLAN1).
• Enable Rapid-PVST+ mode in CONFIGURATION mode.
spanning-tree mode rapid-pvst
Congure RPVST+
OS10(config)# spanning-tree mode rapid-pvst
View RPVST+ conguration
OS10# show spanning-tree active
Spanning tree enabled protocol rapid-pvst with force-version rstp
VLAN 1
Executing IEEE compatible Spanning Tree Protocol
Root ID Priority 32768, Address 3417.4455.667f
Root Bridge hello time 2, max age 20, forward delay 15
Bridge ID Priority 32769, Address 90b1.1cf4.a523
Configured hello time 2, max age 20, forward delay 15
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
------------------------------------------------------------------------
ethernet1/1/5 128.276 128 500 FWD 0 32768 3417.4455.667f 128.146
ethernet1/1/6 128.280 128 500 BLK 0 32768 3417.4455.667f 128.150
Interface
Name Role PortID Prio Cost Sts Cost Link-type Edge
--------------------------------------------------------------
ethernet1/1/5 Root 128.276 128 500 FWD 0 AUTO No
ethernet1/1/6 Altr 128.280 128 500 BLK 0 AUTO No
Select root bridge
RPVST+ determines the root bridge. Assign one bridge a lower priority to increase the likelihood that it becomes the root bridge. The show
spanning-tree brief
command displays information about all ports regardless of the operational status.
• Assign a number as the bridge priority or designate it as the root in CONFIGURATION mode, from 0 to 61440.
spanning-tree {vlan vlan-id priority priority-value}
– vlan-id — Enter a value between 1 to 4093.
– priority priority-value — Enter the priority value in increments of 4096, default is 32768. The lower the number
assigned, the more likely this bridge becomes the root bridge. The bridge priority the valid values are: 0, 4096, 8192, 12288, 16384,
20480, 24576, 28672, 32768, 36864, 40960, 45056, 49152, 53248, 57344, or 61440. All other values are rejected.
Congure root bridge
OS10(config)# spanning-tree vlan 1 priority 4096
View active conguration
OS10(config)# do show spanning-tree active
Spanning tree enabled protocol rapid-pvst with force-version rstp
VLAN 1
Executing IEEE compatible Spanning Tree Protocol
Root ID Priority 4097, Address 90b1.1cf4.a523
Root Bridge hello time 2, max age 20, forward delay 15
Bridge ID Priority 4097, Address 90b1.1cf4.a523
We are the root of VLAN 1
Configured hello time 2, max age 20, forward delay 15
240
Layer 2