I came up through real networks — telecom rollouts, Cisco switching and IP telephony, the whole physical craft of moving packets reliably. Over the last decade that craft was turned inside out. If you learned networking in 2016 and went to sleep until 2026, you'd recognise the fundamentals and almost none of the architecture. Here's the decade that did it.
1. 2016: the box era
Ten years ago, networking meant hardware you could touch. Branch offices linked by expensive MPLS circuits. Traffic hauled back to a corporate data centre so a big on-prem firewall could inspect it. Certification meant the classic Cisco track, and CCNP was the mark of someone who could design and run all of it. The model was coherent and stable — and built entirely around the assumption that the important things lived inside a building.
2. Software eats the WAN
The first crack was SD-WAN. Instead of expensive, rigid MPLS, you could use ordinary internet links intelligently — steering traffic in software, per application, with central policy. It was cheaper and far more flexible, and it began the quiet shift of networking from a hardware discipline to a software one. The box didn't disappear, but the intelligence moved off it and into a controller.
3. The cloud breaks the perimeter
Then the ground assumption collapsed. The applications moved to the cloud, and — especially after 2020 — the users moved to their homes. Suddenly the thing you were protecting and the people using it were both outside the corporate network. Hauling a home worker's traffic back to a data-centre firewall so it could then go out to a cloud app was slow, expensive and faintly absurd. The castle-and-moat model didn't gradually weaken; it stopped making sense.
For twenty years the network was the perimeter. In a single decade that stopped being true, and the whole discipline had to reorganise around a world with no edge.
4. Zero trust and SASE
The answer that emerged has two names. Zero trust is the principle: trust nothing by default, verify every request on its merits — identity, device posture, context — regardless of where it comes from. SASE is the architecture that delivers it: converge the networking (SD-WAN, routing) and the security (secure web gateway, zero-trust access, firewalling) into one cloud-delivered service applied at the edge, close to the user wherever they are. Networking and security, historically separate teams with separate certifications, fused into a single problem.
5. Cisco's certifications follow the reality
You can watch the whole shift in the certifications. Cisco's 2020 overhaul folded automation (DevNet) into the mainstream, and the professional-level security material was rebuilt around zero trust, secure service edge, SD-WAN, cloud security and endpoint posture — with zero trust, SSE and SASE explicitly replacing the traditional VPN. The credential that once certified box configuration now certifies perimeter-less, cloud-first, security-fused networking. The vendor whose hardware supposedly became less central rewrote its flagship track around the new world.
6. What endured
Here's the part that matters if you're deciding whether the old skills were wasted: they weren't. Every one of these new architectures runs on the same fundamentals — routing, addressing, latency, how a packet actually finds its way. A cloud network problem is a routing problem. A zero-trust policy that silently drops traffic is an access-list problem in nicer clothing. The abstractions moved the work up the stack; they didn't repeal the physics underneath. The engineers who struggled this decade were the ones who'd memorised commands. The ones who thrived understood systems, and just kept applying that understanding to each new layer. The fundamentals didn't die — they got more valuable, because now one misunderstanding scales across the whole estate at once. I've written the current, practical version of this argument in Does CCNP Still Matter?. If you're weighing which networking skills to invest in next, ask me.