In community college not 5 years ago, I took the first two of a series of Cisco networking classes designed to prep for certifications such as CCNA. When we ca

In community college not 5 years ago, I took the first two of a series of Cisco networking classes designed to prep for certifications such as CCNA. When we came upon CIDR and VLSM, our instructor (very knowledgeable, down-to-earth, pragmatic) introduced us to various calculators that could assist us, although he did also show us a manual way to graph out each bit. Then he admitted that the VLSM portion of the class had often driven his previous students to tears, and he didn't want to see anyone crying over this anymore.