Cisco Nexus 5000 Series Switch CLI Software Configuration Guide, NX-OS 4.0(1a)N1 (OL-16597-01, January 2009)

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Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
OL-16597-01
Chapter 8 Configuring Rapid PVST+
Configuring Rapid PVST+
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.
To assign Rapid PVST+ port priorities to individual ports, perform this task:
This example shows how to configure the port priority of Ethernet access port 1/4 to 160:
switch# configure terminal
switch(config)# interface ethernet 1/4
switch(config-if)# spanning-tree port-priority 160
You can only apply this command to a physical Ethernet interface.
Configuring the Rapid PVST+ Pathcost Method and Port Cost
On access ports, you assign port cost by the port. On trunk ports, you assign the port cost by VLAN; you
can configure the same port cost on all the VLANs on a trunk.
Note In Rapid PVST+ mode, you can use either the short or long pathcost method, and you can configure the
method in either the interface or configuration submode.The default pathcost method is short.
To set the Rapid PVST+ pathcost method and cost for a port, perform the following task:
Command Purpose
Step 1
switch# configure terminal
Enters configuration mode.
Step 2
switch(config)# interface type
slot/port
Specifies the interface to configure, and enters the
interface configuration mode.
Step 3
switch(config-if)# spanning-tree [vlan
vlan-list] port-priority priority
Configures the port priority for the LAN interface. The
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.
Command Purpose
Step 1
switch# configure terminal
Enters configuration mode.
Step 2
switch(config)# spanning-tree pathcost
method {long | short}
Selects the method used for Rapid PVST+ pathcost
calculations. The default method is the short method.