I forgot to mention - he also talks about Layer 3 features (BGP) and that he has to configure on his switch in the case of XCP. Most folks don't really have an L3 router beyond their firewall appliance. Not needed. And you can't configure BGP there. Boundary Gateway Protocol is for a more serious exposure to the internet and involves interacting with ASN routing tables. Lets just say beyond the scope of the forum. Most folks operate on a L2 network of some sort and don't configure VLANs. There are many exceptions here, I assume but they would tend to be pretty technical already. This stuff is fire and liability to advise about.
I see lots of questions here that probably would help with some simple configuration drawings to show a typical small network translated ( NAT ) environment for newbies. There are other tricks like router on a stick and such that mimick IP telephone connections to be able to use VLANs.