Ever so now and again I'm reminded of why I'm so sure that senior IS managers must have a grasp of the technical basics. I look at recruitment processes for technical staff and see a reliance on certification as a base measure of suitability. Yet that certification, especially vendor certification (Cisco exempted!), tends to leave out the basics and focus on the applied product. So if the senior IS manager doesn't have the basics, how will they know when their technical staff are misleading them? Or when the sales people are...
So during a client's technical team discussion a forum link was circulated as an answer to a question. The question is irrelevant, the fact that the answer on the forum was essentially correct is also irrelevant; what worried me was a bold factual statement made in passing in the answer and the qualification (Microsoft Most Valuable Professional) of the person who posted it.
I had this vision of some senior IS manager somewhere. They've recruited this really capable person, someone whose "high-quality, real-world technical expertise" has been recognised with this MVP award, and this person is someone they are dependent on for technical advice. And this person can make a factual statement in public like
"VLANs are just subnets"
and still be trusted and qualified to provide technical advice on anything vaguely connected to networks? Networks are one of the basics, like an ABC of a modern information system; the concepts need to be understood as a fundamental of doing the job. There are others too; like a good retail manager has worked every shopfloor department before moving on, like a surgeon has been through general medical qualifications before specialising, a CIO should have a grasp of the basics of each function they oversee.
This is why a CIO must have both technical and business expertise, why just management experience in some other field is insufficient to be really good at the job; and why IS management should be seen as professional career in its own right, with required and tested levels of knowledge to be fully qualified.
 For the record... No, a VLAN is not a subnet. A VLAN may have many subnets, or many VLANs a single subnet. Subnets even existed before "Virtual" LANs, and LANs existed before subnets. They are used for different purposes, although they do often correlate. If you (like the MVP) need to brush up, then VLANs and subnets are good articles to read.