So tad belated, but may be able to help you on this (if ever relevant). I studied 'CCNA Routing and Switching' with the online Cisco Academy.
It's been a while since having gone over the actual content (there is a lot of it), but I'm still fluent in Cisco command line (Cisco IOS - Internetwork Operating System). I'm fairly confident at everything from basic network configuration and debug, to LAN, VLAN, and WAN (and other P2P protocols), ACL's, VPN, DHCP, NAT, encryption ...
It almost sounds silly, configuring NAT, DHCP etc on devices when people are used to just using devices and having them just work, with some simple instructions from a guy over the phone (if even that).
I love having to configure everything manually though, especially things like NAT, VLAN's and protocols ... can really set you apart from the general IT community who just follow the "You don't need to know how it works to use it" philosophy.
I actually aspire to hold a CCIE or CCDA one day. ($110,000 to $175,000 USD salary)
But not for the money, I just love data and being able to control it's flow, and having the skills to do what 99.999% of people on Earth can't - yet the application of those skills affects majority of internet users. Crazy thought. I'm just dreaming ...
Well, that would be nice.
One step at a time.