Hi, VTP: 1. Vlan trunking Protocol. VTP is a layer 2 messaging protocol that maintains the Vlan Configuration Consistency by managing the Addition, Deletion and modification of Vlans on a network wide basis. <br> 2. VTP is the heart for the Switches, as without VTP we cannot send and receive any information to any other Switches. VTP is designed to work in an environment where updates are made on the single Switch and are sent through VTP to other switches via Domain. A Domain is a must to be created. <br> 3. When a Switch joins the stack or the stack gets merge, the new switches will get the information from the Stack master. <br> 4. VTP Domain: A VTP domain is also called as a VLAN Management Domain consists of one switch or several interconnected switches or Switch Stacks under the same administrative responsibility showing the same VTP domain. <br> 5. VTP Modes: a. Server Mode : Add, Del and Modify can be done. | b. Client Mode: Do not allow the Administrator to Add, Del and Modify the Vlans. | c. Transparent Mode: Add, Del and Modification can be done but cannot be propagated to other switches. 6. VTP versions: V1, V2 and V3. V3 is the latest version. and VTP off. 7. VTP v3: supports the extended range vlans (1006 to 4094). Supports Private Vlans | Consistency Check. <br> 8. Support for MST.<br> 9. Support for hidden password. Regards, Raja Vuttham.