Another really useful skill is knowing what it looks like to be a customer / end user of one of those networks. Sure, it's fun to crank obscure BGP load-balancing techniques, but you also need to know where the industry as a whole is going technically and business-wise. Tier 1s sell to Tier 2s, big enterprises, content providers, and consumers, and they all need different things. How much is computing staying under the control of the companies that use it vs. migrating out to cloud providers and Something-As-A-Service? What happens to networks as broadcast TV gets replaced by consumers downloading content? What do you know about end-users from hanging out with other college students that the old folks running the ISPs don't understand yet? Some parts of the Tier 1 business depend on providing access to large end user locations, which is more of an issue of zoning, real estate, and geography; other parts want to scale to hundreds of thousands of smaller connections. When I had a job that was more in the field than my current position, something I saw happening all the time was that people who worked for a customer would get a job at one of their vendors, or people who worked for a vendor would get a job at one of their customers. In bigger companies, that may also be internal end users and service organizations in addition to external customers. It's a big way that you build the relationships that lead to getting jobs and to finding people to hire. And yeah, sometimes it means that you need to go learn technologies like Active Directory, either because you might end up working for an enterprise instead of a service provider, or just because your customers will be using it and you need to know how it'll affect their network needs. In addition to learning scripting languages, you really need to learn some basic VMware, because operationally just about everything that doesn't need custom silicon is migrating onto virtual machines. You don't need to have a whole VMsphere N+1 system at home, but at least install the free versions on a PC, build some VMs and some virtual switches and let them talk to each other, do some firewalls, etc. The certification business is useful for a couple of things - giving you some direction in your learning process, telling people who are trying to hire new coworkers something about your skills, and getting your resume past the HR department so the people who actually understand what the jobs are can see it (or at least keeping them from getting in the way if you've made the connections through people you know instead of through HR.)