Displaying STP Information

To display STP information for a VLAN, enter the show span command as follows:

device# show span vlan 4
VLAN 4 BPDU cam_index is 14344 and the Master DMA Are(HEX) 18 1A  
STP instance owned by VLAN 2

This example shows STP information for VLAN 4. The output indicates that the VLAN STP configuration is controlled by VLAN 2. This information indicates that VLAN 4 is a member of a topology group and VLAN 2 is the master VLAN in that topology group.