Cisco Systems N3KC3048TP1GE Configuring the Rapid PVST+ Port Priority, Procedure, Purpose, Step

Configuring Rapid PVST+

Configuring the Rapid PVST+ Port Priority

Procedure

Command or Action

Step 1 switch# configure terminal

Step 2 switch(config)# spanning-tree vlan vlan-rangeroot secondary [diameter dia [hello-time hello-time]]

Purpose

Enters configuration mode.

Configures a software switch as the secondary root bridge. The vlan-rangevalue can be 2 through 4094 (except reserved VLAN values.) The dia default is 7. The hello-timecan be from 1 to 10 seconds, and the default value is 2 seconds.

This example shows how to configure the switch as the secondary root bridge for a VLAN:

switch# configure terminal

switch(config)# spanning-tree vlan 5 root secondary diameter 4

Configuring the Rapid PVST+ Port Priority

You can assign lower priority values to LAN ports that you want Rapid PVST+ to select first and higher priority values to LAN ports that you want Rapid PVST+ to select last. If all LAN ports have the same priority value, Rapid PVST+ puts the LAN port with the lowest LAN port number in the forwarding state and blocks other LAN ports.

The software uses the port priority value when the LAN port is configured as an access port and uses VLAN port priority values when the LAN port is configured as a trunk port.

Procedure

	Command or Action	Purpose
Step 1	switch# configure terminal	Enters configuration mode.
Step 2	switch(config)# interface type	Specifies the interface to configure, and enters interface
	slot/port	configuration mode.
Step 3	switch(config-if)# spanning-tree	Configures the port priority for the LAN interface. The
	[vlan vlan-list]port-priority priority	priority value can be from 0 to 224. The lower the value,
		the higher the priority. The priority values are 0, 32, 64,
		96, 128, 160, 192, and 224. All other values are rejected.
		The default value is 128.

This example shows how to configure the access port priority of an Ethernet interface:

switch# configure terminal switch(config)# interface ethernet 1/4 switch(config-if)# spanning-treeport-priority 160

You can only apply this command to a physical Ethernet interface.

	Cisco Nexus 3000 NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)U3(1)
82	OL-26590-01