Networking introduction

This video is a quick introduction about networking on computers. It covers some high-level concepts, such as packets, TCP/IP, IP addresses, DNS, DHCP, as well as some useful commands. Again since this is a Linux based video a lot of the commands are shown using Linux, though Windows equivalents (ipconfig, arp -a, and ping) are also covered.

This is truly just an introduction of key concepts, and omits more complex topics of setting static IPs, bringing up a network on a Linux server, and complex routing or detailed firewall permissions, etc. These are all important for IT administrator work and I am linking some more useful links below. 

References:

• Netmask and subnet tables: https://dnsmadeeasy.com/support/subnet/ This was actually somewhat glossed over in the recording, as the Gateway address - typically that of the router on the LAN would define the first 3 groups of numbers and the Netmask controls what level of variance is possible. For example - Gateway 192.168.1.1 and Netmask 255.255.255.0 means other IPs of 192.168.1.XXX (where XXX is 2~254) are valid, where Gateway 192.168.1.1 and Netmask 255.255.254.0 means other IPs of 192.168.1.XXX and 192.168.2.XXX are valid.
• Microsoft also has a pretty good description of the concept as well: https://support.microsoft.com/en-us/help/164015/understanding-tcp-ip-addressing-and-subnetting-basics
• More info on TCP/IP: https://searchnetworking.techtarget.com/definition/TCP-IP https://en.wikipedia.org/wiki/Internet_protocol_suite https://www.javatpoint.com/computer-network-tcp-ip-model
• Firewall setting details - using ufw on Ubuntu / Linux Mint: https://www.digitalocean.com/community/tutorials/how-to-set-up-a-firewall-with-ufw-on-ubuntu-18-04
• Firewalld (Red Hat, CentOS and Fedora):
  https://www.digitalocean.com/community/tutorials/how-to-set-up-a-firewall-using-firewalld-on-centos-7
• Firewall rules in Windows 10 (note that the defaults for this are enabled with Windows Defender in the settings):
  https://www.tomshardware.com/news/how-to-open-firewall-ports-in-windows-10,36451.html

Networking is an important part of using computers and tech, and having a basic understanding is really critical to starting on more advanced projects. Like with the other concepts covered in this blog, I hope this is a good starting point.