For a small network VLAN configuration and VLAN trunking configuration is easy to manage. But configuring VLAN and VLAN trunking for large networks with many interconnected switches can be a very difficult task. VLAN Trunk Protocol (VTP) is a protocol created by Cisco to create and manage VLANs for a large network with many interconnected switches and to maintain consistency throughout the network. In other words, switches use VLAN trunking protocol (VTP) to communicate among themselves about VLAN configuration.
The VLAN Trunking Protocol (VTP) is a very useful protocol to create, manage and maintain a large network with many interconnected switches. The VLAN Trunking Protocol (VTP) can manage the addition, deletion, and renaming of VLANs from a central point without manual intervention and VLAN Trunk Protocol (VTP) thus reduces network administration in a switched network.
Currently there are three version of VLAN Trunking Protocol (VTP). The functions of VTP Version 1 and VTP Version 2 are almost similar. The support for Token Ring VLANs is there with VTP V2.
According to Cisco VTP V3 documentation, VLAN Trunking Protocol (VTP) Version 3 introduces the concept of transferring an opaque database in situations where VTP version 1 and VTP version 2 interacted with the VLAN process directly. VTP version 3 includes support for the MST mapping table.
These are the enhancements made on VLAN Trunk Protocol (VTP) V3.
• Protection from unintended database overrides during insertion of new switches
• Support for VLAN numbers up to 4096
• Support for interaction with VTP Version 1 and VTP Version 2.
• Support for a structured and secure VLAN environment (Private VLAN, or PVLAN)
• Option of clear text or hidden password protection
• Configuration option on a per port base instead of only a global scheme
• Optimized resource handling and more efficient transfer of information