VTP stands for Vlan Trunk Protocol; it is a Layer2 messaging protocol is used to maintain the Vlan configuration consistency by managing addition, deletion and renaming of Vlan. When configure a new VLAN on one VTP server, the VLAN is distributed through all switches in the domain. This reduces the need to configure the same VLAN everywhere. VTP is a Cisco-proprietary protocol that is available on most of the Cisco Catalyst series products.
Three types of VTP modes:
Server Mode: - the server mode has full permission to delete, create and alter.
Client Mode: - the client mode have not permit to delete, create and rename the vlans, it only receive information from the server and update accordingly it pass the same information to its clients switch.
Transparent Mode: - it only receive information form server but not update accordingly server. It only forwards the information to its next switch.
Three types of Advertisement
- Subset and
Summary Advertisement: Send every five minutes by a server or client to inform neighbouring switches of what it believes is the current VTP configuration revision number for its management domain. It sends immediately after a configuration change has been made.
Subset Advertisement: This is sent if any change in the VLAN configuration has been made or in response to an advertisement request.
Advertisement request: Solicits both a summary advertisement and a subset advertisement from the server in the management domain.
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