What is VTP ?

VTP
VTP stands for vlan trunking protocol, and its used to automatically update and configure swtiches on VLAN configuration. VTP maintains a VLAN configuration consistency by managing the addition, deletion, and renaming of VLANs across multiple Cisco switches in a network.

VTP has three modes. These mode are:

1)VTP mode server
2)VTP mode client
3)VTP mode transparent

VTP Mode (server/client/mode)

Server
VTP server transits all configurations to other switches in the network. In this mode you can create, modify, and delete VLANs. Server advertise their VLAN configuration to other switches in the same VTP domain.

Client
VTP mode client cannot create, modify, of delete vlans from the network. You can only receive VLAN information and advertise to others.

Transparent
Transparent is used for local VLAN that other switches do not have access to. The Transparent switches forward VTP advertisements to VTP clients and VTP servers.

Other VTP components

VTP Domain-Consists of one or more interconnected switches. VTP allows you to separate your network into smaller management domains to help reduce VLAN management. On top of that it limits the extent to which configuration changes are propagated in the network if an error occurs.

VTP Advertisements-VTP uses a hierarchy of advertisements to distribute and synchronize VLAN configurations across the network.

VTP Frame
A VTP frame consists of a header field and a message field. The information is inserted into
a header field and an Ethernet frame. The Ethernet frame is then encapsulated as 802.1Q trunk.

In the VTP header field the following information is found
Domain name – identifies the domain in the switch
Version – What VTP are set (ex.. VTP 1, VTP 2, VTP 3
Configuration Revision Number – The current configuration revision number on the swtich.

VTP Pruning
VTP Pruning works by restricting broadcast traffic to only those trunks links that must carry the traffic. Remember, by default, VTP pruning is disabled.
VTP version 2 features support for Token Rig, consistency check, unrecognized TLV support, version-independent and transparent mode.