Excellent Series on DMVPN with MPLS, IVRF’s, and FVRF’s by Khawar Butts
A topic I am working to learn is Front Door and Internal VRF’s. I have linked a few very excellent resources below.
Below is a link to a blog from Denise “Fish” Fishburne.
I am taking this Khawar’s Annual pass and he has some great videos that are free. If you want to learn about IVRF’s and EVRF’s I recommend these.