tl/dr: Here is a nice chart for you! I created the below chart a few years ago to post up for reference some of my coworkers would forget what our subnet mask was suppose to be. It didn't really work ...

A subnet allows the flow of network traffic between hosts to be segregated based on a network configuration. By organizing hosts into logical groups, subnetting can improve network security and ...

Okay, first assume that I am completely f*****g stupid BUT, desperate to understand subnet masking. I'm reading the MCSE TCP/IP guide (for some reason I enjoy it) and have reached the Subnet chapter.