Hello,
VTP is used to advertise the existance of Vlans in a campus network under a common amministration providing information about the vlan-number and some other fields like vlan MTU SAID.
earlier versions of VTP ( 1 and 2) have no concept of private Vlans so the need for VTP transparent.
In other words: if the private vlans were advertised ( if the node would be in VTP server mode) other switches may use them as standard vlans defeating the purposes that led to private vlan introduction because VTP cannot tell that they are private ( no fields flags in the VTP message).
VTP version 3 might remove this limitation
yes it can see:
http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/pvlans.html
>>>>Because VTP versions 1 and 2 do not support private VLANs, you must manually configure private VLANs on all switches in the Layer 2 network. If you do not configure the primary and secondary VLAN association in some switches in the network, the Layer 2 databases in these switches are not merged. This situation can result in unnecessary flooding of private VLAN traffic on those switches.
VTP version 3 does support private VLANs, so you do not need to manually configure private VLANs on all switches in the Layer 2 network.
Hope to help
Giuseppe
