I’ve been slowly working my way though a list of skills to learn, both to put on my resume and as personal growth. Networking is the next thing on this list. I am not sure what I am looking for, but I want to start another project. I have built many a personal computer, but the world of networking is a pretty foreign concept to me.
I have experience with building computers and a minor glance at the network-side of things. I’ve set up a Pi-Hole or two and set a basic CUPS server up on a RPi0w, but beyond that, I have no idea what I’m doing, or even what the possibilities are. I just see posts like this and think that it’s a pretty cool hardware project.
Is there any resources you recommend to start learning, maybe what the hardware does? From my outsider’s perspective, I see a lot of people’s racks have at least a router, switch, and firewall, along with various other machines.
Not necessarily in this order:
Learn the OSI and TCP/IP layer models.
Learn the fundamentals of IPv4 and IPv6. (Absolutely learn to count bits for IPv4)
Learn and understand the use-cases for routers, switches, and firewalls.
Learn about DNS. (Domain Name System)
Learn about DHCP. (Dynamic Host Configuration Protocol)
Learn important Port Numbers for important Services. (SSH is Port 22, for example. The range of port numbers from 1024 to 49151 are “registered ports” that are generally always the same)
Learn about address classes. (A, B, C are the main ones)
Learn about hardware addresses (MAC address) and how to use ARP to find them.
And more! This is just off the top of my head. Until you’ve studied a lot more, please, for your own sake, don’t open your selfhosted ervices to the wider internet and just keep them local.
And just for fun, a poem:
I think that I shall never see
A graph more lovely than a tree.
A tree whose crucial property
Is loop-free connectivity.
A tree that must be sure to span
So packets can reach every LAN.
First, the root must be selected.
By ID, it is elected.
Least cost paths from root are traced.
In the tree, these paths are placed.
A mesh is made by folks like me,
Then bridges find a spanning tree.
— Radia Perlman Algorhyme
Classful networking is well past dead, that’s kinda pointless. Learn VLSM and general subnetting basics instead.
I mean, isn’t it important to understand the fundamentals so you can understand VLSM better?
Like math, a lot of this knowledge works better when you know the fundamentals and basics, which help you conceptualize the bigger ideas.
On a personal level, I would have had a lot harder time understanding VLSM if I hadn’t had the basic fundamentals of traditional subnetting and classful networking under my belt.
There’s nothing inherently important to classful networking you learn that’s necessary for VLSM. They amount to common convention based on subnet size, and even then nearly nobody actually uses A or B sized subnets except as summary routes, which again, is not inherent to classful networking.
Classful networking has been obsolete for thirty years for good reason, you gain nothing from restricting yourself in that way.
How are you “restricting” yourself by learning that it exists? Nobody is saying “learn about it and use it and never consider anything else.” They asked what fundamentals they should know for networking, and I dumped what I considered the “fundamentals.”