I intend to build up this guide into a series of more complex “lessons” so eventually we can read packets as they are on the wire and you will be able to interpret what you are seeing without too much difficulty.
Time to start with the basics. In order to understand and read packets, we need to know the fundamentals. How do computers and network communicate? Essentially by binary and hexadecimal. This is a series of zero’s and one’s and the numbers 0 to 9 with the letters A to F.
When I was taught this in school, some 20ish years ago, I honestly found it a bit complicated, but looking back it was only complicated due to the way it was taught. Hopefully this methodolgy is simple for you to understand.
Counting in binary is not too difficult, the values can only be a 0 or a 1, an off or on value. However what the off or on values represent is the important ‘bit’.
You essentially have 8 bits in a byte and this makes binary reasonably straight forward, for counting I find it best to create a quick table, this allows me to visually count, rarther than attempting to work out everything in my head.