you are overthinking this bro, I say to myself, self, what would anyone port scan? I says to self, self, it has to be a building of some sort, self agreed.
I can only imagine what you are either inquiring about or about to do or what so all I would say is what you are trying to do worth your freedom, in prison, because you may violate federal laws and you will go to federal prison and you WILL do 80% of your time, that's why they sentence in months, they mean that sh!t!! I spent 4 years in prison, state that is, you really don't want to risk that port scanning some dumb crap right? I mean if there is a payday in it then take your chances, I wouldn't, younger I would have 🙂
The only real thing you are going to do is find mostly junk you can't use as this huge migration to cellphones, tablets and real deal enterprise protection will just be an endless sea to nowhere.
If you are port scanning your own network you will just slow it down.
Just use FING, from the app store, stealthy and has almost no impact.
Peace