I have worked with and taught Linux for over eight years, the majority of my work has been with Debian, Redhat and SUSE in that order. It is so important to have broad base of knowledge. The LPIC certifications tick all of the boxes. I used the LPIC1 & 2 books whilst training my competitor for WorldSkills 2013, he gained the highest point score the UK has achieved in the history of the IT Network Systems Administration competition.