the ideas behind VTP & DTP are different, then why do we need to make sure that the VTP domain on both sides is the same otherwise the DTP will not work?
1 Answer
This question is very similar to this other question: Whats the difference between VTP and DTP
You do not actually need VTP at all to use DTP but if you want VTP to work and you want DTP to work then it is only reasonable that for VTP to work, you need to make sure the VTP domain configuration is consistent on all connected switches.
DTP is not specifically related to VTP though if you use VTP and do not configure it correctly, your VLAN configuration on the various switches will be inconsistent which may prevent DTP from forming appropriate Trunk configuration where desired.
