Brocade MLX Series and Brocade NetIron XMR Diagnostic Guide ...

4Spanning Tree Protocol and derivativesSTP debug commandsThis section describes the debug commands for STP, MSTP, and RSTP environments.CAUTIONEnabling diagnostic commands may degrade system performance. These commands are bestused to troubleshoot specific problems while working with qualified Brocade service technicians.Whenever possible, troubleshoot your system during periods of low network traffic and useractivity to preserve system performance.NOTEBecause STP and RSTP debug commands are virtually identical, only STP commands are describedin detail in this chapter.debug spanning-treeSyntax: [no] debug spanning-tree [config-bpdu | event | port [ethernet | pos] | reset | show | tcn-bpdu | verbose | vlan ]This command generates information about all BPDUs and spanning tree events (by default) orspecific events as defined by the variables shown in the syntax line. In many cases, genericdebugging is not useful. If multiple STP instances are configured, it can be difficult to identifycontent for a specific instance from the extensive output that may be generated. Use the debugspanning-tree port and debug spanning-tree vlan commands to define specific instances fordebugging.• config-bpdu - Generates information about STP configuration bridge protocol data units(BPDUs).• event - Generates information about STP non-BPDU events (timer, configuration, and so on).• port - Restricts STP debugging to specific ports.• ethernet - Restricts STP debugging to a specific Ethernet interface.• pos - Restricts STP debugging to a specific POS interface.• reset - Resets all STP debugging parameters to the default.• show - Displays current STP debug settings.• tcn-bpdu - Enables or disables STP TCN BPDU debugging.• verbose - Enables or disables STP verbose debugging mode.• vlan - Restricts STP debugging to specific VLAN.This command generates information about all STP activity and events. Command outputresembles the following example.Brocade# debug spanning-treeSTP: debugging is onSTP: Sending Config BPDU - VLAN 3 Port 2/30000 00 00 00 800000000001c042 00000000800000000001c042 8043 0000 0000 0000 0000STP: Sending Config BPDU - VLAN 3 Port 2/40000 00 00 00 800000000001c042 00000000800000000001c042 8044 0000 0000 0000 0000STP: Sending Config BPDU - VLAN 2 Port 2/188 Brocade MLX Series and Brocade NetIron XMR Diagnostic Guide53-1002426-02