UMN:CLI
User Manual
V8102
384
PVSTP is activated after selecting PVSTP mode using
spanning-tree mode rapid-pvst
command. In PVSTP, you can configure the current VLAN only. If you input VLAN that
does not exist, error message is displayed.
For the switches in LAN where dual path does not exist, Loop does not generate even
though STP function is not configured.
To disable a configured PVSTP, use the following command.
Command
Mode
Description
no spanning-tree
vlan VLANS
Global
Disables PVSTP in VLAN.
VLANS: VLAN ID (1-4094)
9.4.8.2
Root Switch
To establish PVSTP function, a root switch should be chosen first. Each switch has its
own bridge ID, and one of the switchs on same LAN is chosen as a root switch by com-
paring with their bridge IDs. A bridge ID, consisting of the switch priority and the switch
MAC address, is associated with each instance. However, you can configure the priority
and make it more likely that the switch will be chosen as the root switch. The switch hav-
ing the lowest priority becomes the root switch for that VLAN.
To configure the switch priority for a VLAN, use the following command.
Command
Mode
Description
spanning-tree vlan VLANS prior-
ity
<0-61440>
Global
Configures a priority for specified VLAN.
VLANS: VLAN ID (1-4094)
0-61440: priority value in increments of 4096 (default:
32768)
no spanning-tree vlan VLANS
priority
Deletes a configured priority for specified VLAN.
9.4.8.3
Path-cost
After deciding Root switch, you need to decide to which route you will forward the packet.
To do this, the standard is path-cost. Generally, path-cost depends on transmission speed
of LAN interface in switch. In case the route is overload based on Path-cost, it is better to
take another route.
By considering the situation, the user can configure Path-cost of Root port in order to des-
ignate the route on ones own.
To configure the path-cost value for specified vlan in PVSTP, use the following command.
Command
Mode
Description
spanning-tree vlan VLANS
cost
<1-200000000>
Interface
[XE/GE]
Configures path-cost to configure route
on user
’s own.
VLANS: VLAN ID (1-4094)
no spanning-tree vlan VLANS
port PORTS
cost
Deleted a configured path-cost.