2.1.d Implement and troubleshoot trunking

2.1.d [i] VTPv1, VTPv2, VTPv3, VTP pruning

from: http://etherealmind.com/cisco-vtp-transparent-mode-discard-risk-transparent-client-server/

The Modes

A Switch in VTP Server mode will always actively participate in sending and receiving VTP and synchronising the VTP data file. Regardless of version.

A Switch in VTP Client mode will always actively participate in VTP data file synchronisation. Regardless of version.

A switch in VTP v1 Transparent Mode will not send, receive VTP data or participate in file synchronisation.

A switch in VTP v2 Transparent Mode will send, receive VTP data, but doesn’t participate in VTP file synchronisation.

The only configuration that DOES NOT pass VTP packets is a switch configured in VTPv1 Transparent Mode and VTPv3 in off mode.

For VTPv3, the difference is much clearer. VTPv3 has four modes: server, client, transparent and off. The difference between transparent and off is the termination of received VTP messages instead of relaying them. With VTP version 3, off mode can be configured globally or on a per port (for example trunk) base. The off mode was formerly only available with CAT OS. The configuration of off on an interface will apply to all VTP instances.

Also note that VTPv3 will propagate VLANs above 1024, while VTPv1 & 2 do not. Another historical artefact.