Try this: print out the entire running configuration from a device on your network, any device with which you're familiar. Sit down with the printed pages away from a computer, and attempt to annotate line by line the purpose of each configuration statement. Sounds easy, right? You might be surprised by how much of the config, although familiar, cannot be readily tied to a purpose. Keep a separate list of the lines you can't explain and research them.
I discovered how challenging this can be several years back when I set out to document a configuration template. Despite being familiar with the entire configuration, there were a number of lines which I simply had never bothered to investigate. It was a little embarrassing having to research these neglected yet significant configuration details which, for years, I had blindly copied and pasted without thought.
This exercise can serve a number of purposes:
- Getting comfortable with a configuration template for a new device or network
- Flagging extraneous or deprecated configuration items for removal
- Testing the skill level of a new employee or candidate for hire
If implementing this exercise as an evaluation of junior staff, I suggest keeping the initial test results. Have him or her repeat the same exercise a month or two later, and compare the two outcomes to gauge progress.