HP Manager Software manual Select Spanning Tree Properties

202CHAPTER 5: CONFIGURING WX SYSTEM AND ADMINISTRATIVE PARAMETERS

Backbone Fast Convergence Backbone fast convergence accelerates a port’s recovery following the failure of an indirect link. Normally, when a forwarding link fails, a bridge that is not directly connected to the link does not detect the link change until the maximum age timer expires.

Backbone fast convergence enables the WX switch to listen for bridge protocol data units (BPDUs) sent by a designated bridge when the designated bridge’s link to the root bridge fails, and immediately verifies whether BPDU information stored on a port is still valid. If the BPDU information on the port is no longer valid, the bridge immediately starts the listening stage on the port.

If you plan to use the backbone fast convergence feature, you must enable it on all the bridges in the spanning tree.

CAUTION: The backbone fast convergence feature is not compatible with switches that are running standard IEEE 802.1D Spanning Tree implementations. This includes switches running Rapid Spanning Tree or Multiple Spanning Tree.

Uplink Fast Convergence Uplink fast convergence enables a WX switch that has redundant links to the network core to immediately change the state of a backup link to forwarding if the primary link to the root fails. Uplink fast convergence bypasses the listening and learning states to immediately enter the forwarding state.

The uplink fast convergence feature is applicable to bridges that are acting as access switches to the network core (distribution layer) but are not in the core themselves. Do not enable the feature on WX switches that are in the network core.

To configure fast convergence features:

1In the Organizer panel, navigate to the WX switch you want to configure.

2Expand the switch to see the configuration options.

3Select Spanning Tree Properties.

4Select Config > Edit. The Modify Spanning Tree Properties dialog box appears.

5To switch to an alternate port when the root port fails, select Enable Uplink Fast.

6To enable the backbone fast convergence feature, select Enable Backbone Fast.