HP 6120XG HP ProCurve Series 6120 Blade Switches Advanced Traffic Management G - Page 162

Multiple Instance Spanning-Tree Operation Troubleshooting an MSTP Configuration Troubleshooting an MSTP Configuration Command show spanning-tree root-history show spanning-tree debug counters show spanning-tree debug-counters instance < instance-id > show spanning-tree debug-counters instance < instance-id > ports Page 4-58 4-61 4-62 4-64 This section describes the show spanning-tree commands that you can use to monitor, troubleshoot, and debug the operation of a multiple-instance spanning-tree configuration in your network. Note that the show spanning-tree commands described in this section allow you to troubleshoot MSTP activity in your network by focusing on increasingly specific levels of operation. For example, you can display debug information for: ■ All MST instances ■ All ports used in one MST instance ■ A specific port or several ports used in one MST instance Also, you can display the change history for the root (bridge) switch used as the single forwarding path for: ■ All MST regions, STP bridges, and RSTP bridges in an STP network ■ All VLANs on MSTP switches in a region ■ All VLANs on MSTP switches in an MST instance Displaying the Change History of Root Bridges The show spanning-tree root-history command allows you to display change history information (up to 10 history entries) for a specified root bridge in any of the following MSTP topologies: ■ Common Spanning Tree (cst): Provides connectivity in a bridged network between MST regions, STP LANs, and RSTP LANs. ■ Internal Spanning Tree (ist): Provides connectivity within an MST region for VLANs associated with the default Common and Internal Spanning Tree (CIST) instance in your network (VLANs that have not been mapped to an MST instance). 4-58