what is difference between vtp version 1 and 2?
VTP Version 2 (V2) is not much different than VTP Version 1 (V1). The major difference is that VTP V2 introduces the support for Token Ring VLANs. If you are using Token Ring VLANs, you need to enable VTP V2. ... Protection from the "wrong" database accidentally being inserted into a VTP domain.