Yep, I was doing network programming back in the late 90's and you pretty much had to have a good grasp of winsock and linux network calls and responses because the level of abstraction was much lower.

That said I can't recall any of that stuff mattering in the stuff I do for work for quite some time and most of it is a google search away.

That interview was just weird, it was like asking the boiler pressure for a steam train to someone who was a master engineer working on electric trains.