I think learning the basics of subnetting, vlaning, switching, and routing and IOS were the most important parts of it. I don’t think I ever needed to really know how to configure a T1 or various other dead technology. But pretty much every vendor uses a clone of IOS and knowing the proper way to logically configure a network is important. I’ve seen so many abhorrent hacked together networks in my day.

I worked for an ISP who paid for mine back in the day. Took like a 3 day e-learning course and then examine. The real world experience was probably the best way to learn

Echoing what others have said, the CCNA itself just checks a box, but it does cover the fundamentals well. Networking technology is still using the same protocols, and every vendor is just a reskin of old school Cisco CLI. Especially new Cisco stuff… there really hasn’t been any meaningful protocol level innovation in a while.

The best way to learn it do download packet tracer and GNS3, then just start building stuff. Think about the applications for the real world, right now redundancy is a huge deal because everything is managed remotely, so being able to build a network that can degrade without outright failing is a highly in demand skill set.

I think I’ve gotten as far as CCNP and I only made it because company was paying for courses and certification. Learning some of the things was painful and boring, especially proprietary cisco stuff that at the time was almost dead already. I think there was a funny video course that actually was engaging by Lazarus Dias (or something like that).

I don’t have any network certificates. And IMO, I’m not entirely enthused about them, but I recognize they’re a required checkbox for getting one’s foot in the door, kinda like having a college degree, esp for certain government employers. But I digress.

My networking training was on-the-job, where my mentor basically gave me a hard-copy version of this book: The All-New Switch Book, 2nd Edition, by Seifert and Edwards. In this case, “all-new” refers to 2008. But that’s alright because the fundamentals of modern computer networks have not substantially changed, even as we push beyond 400 Gbps and use MPLS to forward Metro Ethernet, or whatever.

In the end, a fundamental understanding involves switching and routing, the whole OSI layer model and practical realizations of it, Ethernet in detail, IP (Legacy + v6) in detail, and best-practices for network design. What a CCNA certificate might specifically cover is the Cisco-specific CLI syntax for setting up and maintaining a network, but knowing the fundamentals means it’s easy to manage any vendor’s equipment, or even virtual networks for VMs or hyperscalar cloud environments.

I got bored halfway through and quit. Its very dry. I was using Wendell Odom’s ccna textbook from the library.