Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 717

tagged 1/0/32 exit Debugging and Verifying MSTP Configurations To debut and verify MSTP configuration, use the following commands. • Display BPDUs. EXEC Privilege mode debug spanning-tree mstp bpdu • Display MSTP-triggered topology change messages. debug spanning-tree mstp events Examples of Viewing MSTP Information To ensure all the necessary parameters match (region name, region version, and VLAN to instance mapping), examine your individual routers. To show various portions of the MSTP configuration, use the show spanning-tree mst commands. To view the overall MSTP configuration on the router, use the show running-configuration spanningtree mstp in EXEC Privilege mode. To monitor and verify that the MSTP configuration is connected and communicating as desired, use the debug spanning-tree mstp bpdu command. Key items to look for in the debug report include: • MSTP flags indicate communication received from the same region. • As shown in the following, the MSTP routers are located in the same region. • Does the debug log indicate that packets are coming from a "Different Region"? If so, one of the key parameters is not matching. • MSTP Region Name and Revision. • The configured name and revisions must be identical among all the routers. • Is the Region name blank? That may mean that a name was configured on one router and but was not configured or was configured differently on another router (spelling and capitalization counts). • MSTP Instances. • To verify the VLAN to MSTP instance mapping, use the show commands. • Are there "extra" MSTP instances in the Sending or Received logs? This may mean that an additional MSTP instance was configured on one router but not the others. The following example shows viewing an MSTP configuration. Dell#show run spanning-tree mstp ! protocol spanning-tree mstp name Tahiti revision 123 MSTI 1 VLAN 100 MSTI 2 VLAN 200,300 Multiple Spanning Tree Protocol (MSTP) 717