I worked an internship where I spent the summer setting up new equipment for a large corp that was replacing everything that AT&T had installed and managed with their own stuff. Nearly every office had their own ASN, everyone else got regular broadband or just a box of aircards depending on the number of users. I knew nothing about networks other than setting up my own consumer router at home so it was a pretty fun learning experience. I always got a smile on my face when I finally got vRouter to peer with our dummy AS in the office then we'd pack it all up and bring it out for installation over the weekend. I got offered a job to come back after I graduated but turned it down for something that paid better and was a lot more interesting. Honestly, I probably would be making more money as a network engineer now if I stuck with it.