HP ProCurve 9304M Installation And Configuration Manual page 255

For example, in Figure 8.23, Routing Switch 10 and Routing Switch 30 receive legacy BPDUs from Routing
Switch 20. Ports on Routing Switch 10 and Routing Switch 30 begin sending BPDUs in STP format to allow them
to operate transparently with Routing Switch 20.
Figure 8.23 802.1W Bridges with an 802.1D Bridge
Routing Switch 10
802.1W
Once Routing Switch 20 is removed from the LAN, Routing Switch 10 and Routing Switch 30 receive and transmit
BPDUs in the STP format to and from each other. This state will continue until the administrator enables the force-
migration-check command to force the bridge to send RSTP BPDU during a migrate time period. If ports on the
bridges continue to hear only STP BPDUs after this migrate time period, those ports will return to sending STP
BPDUs. However, when the ports receive RST BPDUs during the migrate time period, the ports begin sending
RST BPDUs. The migrate time period is non-configurable. It has a value of three seconds.
NOTE: The IEEE standards state that 802.1W bridges need to interoperate with 802.1D bridges. IEEE
standards set the path cost of 802.1W bridges to be between 1 and 200,000,000; whereas path cost of 802.1D
bridges are set between 1 and 65,535. In order for the two bridge types to be able to interoperate in the same
topology, the administrator needs to configure the bridge path cost appropriately. Path costs for either 802.1W
bridges or 802.1D bridges need to be changed; in most cases, path costs for 802.1W bridges need to be changed.
Configuring 802.1W Parameters on an HP Device
The remaining 802.1W sections explain how to configure the 802.1W protocol in an HP Chassis device.
Chassis devices are shipped from the factory with 802.1W disabled. Use the following methods to enable or
disable 802.1W. You can enable or disable 802.1W at the following levels:
• Port-based VLAN – Affects all ports within the specified port-based VLAN. When you enable or disable
802.1W within a port-based VLAN, the setting overrides the global setting. Thus, you can enable 802.1W for
the ports within a port-based VLAN even when 802.1W is globally disabled, or disable the ports within a port-
based VLAN when 802.1W is globally enabled.
• Individual port – Affects only the individual port. However, if you change the 802.1W state of the primary port
in a trunk group, the change affects all ports in the trunk group.
Enabling or Disabling 802.1W in a Port-Based VLAN
Use the following procedure to disable or enable 802.1W on a device on which you have configured a port-based
VLAN. Changing the 802.1W state in a VLAN affects only that VLAN.
USING THE CLI
To enable 802.1W for all ports in a port-based VLAN, enter commands such as the following:
HP9300(config)# vlan 10
HP9300(config-vlan-10)# spanning-tree 802-1w
Syntax: [no] spanning-tree 802-1w
USING THE WEB MANAGEMENT INTERFACE
You cannot enable or disable 802.1W on port-based VLAN using the Web management interface.
Configuring Spanning Tree Protocol (STP) and Advanced STP Features
Routing Switch 20
802.1D
Routing Switch 30
802.1W
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