this post was submitted on 10 Jun 2024
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networking

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[question] I want to learn - where do I start? (lemmy.world)
submitted 5 months ago by [email protected] to c/[email protected]
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[I hope this belongs here - if not, lmk and I'll delete the post. I've been mainly lurking here so far]

In a month I'll be in charge of "IT-stuff" in a small office. People are generally happy if there is internet and VoIP is working. I'd like to take the opportunity to learn what I can, while I have the chance. And maybe/hopefully contribute to make it a bit better. For now I want to look into how I should configure wifi and access for office/guests (and devices that are used obv.) Thing is, I don't know where to start and what I actually can do. Do I just google "how to configure wifi in the office?" and go from there? (I'm a bit hesitant to do that since I'll not be able to tell if what I find is good) Is there any good reference material you would suggest? Any suggestions are appreciated.

I studied business informatics (but it's been a while) so I'm not completely clueless (but still clueless hehe).

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[โ€“] [email protected] 11 points 5 months ago* (last edited 5 months ago) (1 children)

I would start with getting a good idea of how things actually work, like the TCP stack, DHCP, Wifi, etc. Learning these basics will help a lot in diagnosing issues, because you'll be able to isolate it to specific parts of the network to look at. Having a good grasp of the basic principles of networking has really helped me a lot in figuring out issues.

A lot of the other stuff - like "how do I configure wifi in the office" - is highly vendor-dependent. The process for, say, setting up a guest network is going to be different depending on what hardware you have. But if you have a good grasp of the basics of networking you'll be able to figure out what those settings actually do.

Sadly, I learned a lot of this stuff through trial and error and long frustrating attempts at getting wifi and routing and VPNs to actually work, so I don't have any materials to recommend.

Edit: Another tip is to be able to build models of the systems you're making so you can test changes. It's incredibly helpful to have an environment you can break and rebuild quickly to test things. This goes for basically everything sysadmin related.

[โ€“] [email protected] 4 points 5 months ago* (last edited 5 months ago) (1 children)

Big focus on the model system if possible. My partner still reminds me about the time I said a minor update in my stack* would take "a few minutes" ๐Ÿ˜…

[โ€“] [email protected] 4 points 5 months ago (1 children)

I work with customers a lot, and it's always impressive when I say "Yeah, just do these two things and it'll fix your issue" and then it does. What they don't see is the hours and hours I spent breaking shit, resetting the test environment, and breaking it again.

It's like the apocryphal tale of the engineer who charged for knowing where to tap the hammer.

[โ€“] [email protected] 1 points 5 months ago (1 children)

Thanks for the suggestions! When you say model, do you mean the OSI model or just an actual network where I can tinker? Lettuce eat lettuce was kind enough to make a list of the basics - I'll use that as a guideline. Others have provided material as well; it seems I do not need to worry about filling time :)

[โ€“] [email protected] 3 points 5 months ago

Yep, an actual model of your network that you can tinker with

[โ€“] [email protected] 4 points 5 months ago* (last edited 5 months ago) (2 children)

Look up "CompTia Network+ course"

Watch everything in the "Power Cert" series, then watch everything in the "Professor Messer" series.

You won't get through everything in a month unless you are a really fast learner, but you can get through a large amount of content.

Complete both courses, and you will have a solid base level of understanding for computer networking.

The key things to know IMO:

  1. The whole OSI model top to bottom for troubleshooting. If I ask you, "What's the difference between a layer 2 and a layer 3 switch?" You should be able to instantly answer.
  2. Understand IP addressing well. Know what they are, why they work they way they do, and how they apply in a basic network. You should know what CIDR is.
  3. Understand subnetting well. It will confuse you at first, keep watching videos on it until you actually understand it.
  4. Know what DHCP and DNS are and how they are used in a network. This will be CRITICAL to effectively troubleshoot a network problem. A huge number of networking issues boil down to problems with DHCP, or problems with DNS.
  5. Understand VLANs and how they are used and why they are important.
  6. Understand network ports, memorize the most common dozen or so. Know what and how they work and why they matter for security.
  7. Understand the basics of packet anatomy, what they are, how they are formed, packaged, sent, routed, received, unwrapped, and responded to.
  8. Understand VPNs at a basic level and how they work. Know the difference between an IPsec implementation, an OpenVPN implementation, and an overlay network like TailScale. Understand why somebody would chose one over the others.
  9. Practice basic commands and tools like ping, tracert/traceroute, and nmap. These are incredibly useful and necessary to troubleshoot connectivity issues. I use them on a weekly basis at my job.

That all should get you going. It's intimidating, but very rich and rewarding when you start to get it.

And of course, practice practice practice!!! You will NOT learn by just sitting in front of your screen and watching the videos. Get into the command line and start messing around. Grab an old tower or laptop, throw a Linux distro on there and play with SSH, ping, nmap, Uncomplicated Firewall (UFW), start opening and closing ports. Tell certain services like SSH to listen on different ports than the default port 22. Etc.

[โ€“] [email protected] 2 points 5 months ago (1 children)

Thanks so much, especially for the checklist of stuff I need to know. I know some of the stuff (or at least some basics) from an IT support job with a "historically grown" campus network hehe. Some acronyms I haven't even heard. Also: sounds like a good reason to finally install linux again.

[โ€“] [email protected] 1 points 5 months ago

No prob! Yeah just fill in the gaps of what you already know, always keep learning.

[โ€“] [email protected] 1 points 5 months ago

Eh, I think 1&7 aren't all that important. Sure, understanding the difference between a dumb switch and a smart switch is absolutely important, but the actual OSI layers isn't that important. Likewise with packat structure.

The important thing imo is to understand that networks are layered and what the tradeoffs and benefits are for generally going higher, but the specifics are super easy to reference later when needed (rare).

In general, don't get caught up in memorizing stuff, focus instead on practical ways to practice concepts. Set up a VLAN, configure QOS on a smart switch and then on a router, configure a guest LAN with no access to anything on the LAN, etc. Most people learn better by doing, so spend your time doing as much of that as you can.

[โ€“] [email protected] 3 points 5 months ago

https://youtube.com/playlist?list=PLxbwE86jKRgMpuZuLBivzlM8s2Dk5lXBQ

[โ€“] [email protected] 2 points 5 months ago (1 children)

http://intronetworks.cs.luc.edu/

[โ€“] [email protected] 1 points 5 months ago (1 children)

Thanks for the material! I'll check it out. Not supporting https was a bit eyebrow-raising at first hehe.

[โ€“] [email protected] 1 points 5 months ago

It makes sense to me; educational material should be accessible as far and wide as possible

[โ€“] [email protected] 1 points 5 months ago (1 children)

Use available tools, what concepts are you stuck on?

https://www.freecodecamp.org/news/osi-model-networking-layers-explained-in-plain-english/

[โ€“] [email protected] 1 points 5 months ago

Nothing yet, I was a bit lost on where to start. People here were kind enough to give me a few good starting points, so I think I'll go from there. Thanks for linking the explanation of the OSI-model! I remember that from uni, not much of the actual content though. From what I heard in this thread is seems like a good place to go from.