What command provides real-time output of VTP event information?

The command that provides real-time output of VTP (VLAN Trunking Protocol) event information is "debug sw-vlan vtp events." This command is specifically designed to display events and notifications that occur within the VTP domain, allowing network administrators to monitor and troubleshoot VTP-related activities as they happen.

When using this command, network professionals can see information about VTP message transmissions, changes in VLANs, and updates to the VTP database in real-time. This is particularly useful for ensuring that VLAN configurations are consistent across switches in a network and for identifying any issues during VTP operations that could affect network performance or connectivity.

By focusing on VTP events, this command provides insights that are critical for maintaining a functional and efficient switching environment, especially in large, complex networks where VLAN management is vital. This capability to observe immediate changes helps in making informed decisions and quickly rectifying potential problems as they arise.