I have noticed that there are communitymembers that have difficulty to understand the basics of networking and subnetting. While this is a sysadmin subject, it would be good for non admins to get some ideas about basic networking and subnetting.
Back in 1999 when I started in ICT, I had no idea how networking worked. I was that guy the family and friends asked when they needed to configure their mouse or modem. Or just install a program or even an OS.
That was the time when anyone who could find the on/off button of a computer could get a job in ICT. Of course most of the people that tried a job in ICT and didn’t study for it, went out fast enough. I decided I wanted to go further and started with learning those networking basics.
The best resource I found back then and still recommend (after 15+years) is http://www.ipprimer.com/#/
I printed this on paper and read it, read it again, again and again, until I understood tcp/ip and subnetting. This was a huge asset when tackling networking problems ever since.
Tip: use archive.web to find the “all on 1 page” overview so you can print it on paper and read offline: https://web.archive.org/web/20040603042926/http://www.ipprimer.com/section.cfm