Talked about local computer DNS stuff like the hosts file and the local DNS Resolver cache that the OS maintains. Then how there are things that might change the "http" request to "https" (HSTS, DANE, browser policies, even ISP policies at times). Then talked about DNS resolution and recursive DNS queries and how there is a hierarchy of DNS all the way to the 13 root servers. Also talked about Autonomous Systems and BGP. I think I touched on public key/private key authentication as well.