INE Vol 1 - Lab 26 - finished - Mulicast over MPLS VPNs

I completed this lab, albeit, I had to cheat and look at the solutions for some parts since I wasn't sure what to do.

Question:

1. What is the purpose of MDT under the VRF?

I suppose, I'll Cisco Univercd or google it.

Also my verifications didn't come up. When I do a "show ip pim vrf SW1-SW2 neighbor" I don't actually see the tunnel0 interface of R3 or R6. The tunnel interface is up/up though.

Think I have to read about Multicast over MPLS A LOT more.