VLSM / CIDR Subnet Calculator - Apps on Google Play
IPv4 Subnet Calculator Console Version - TerrorFlatRider
VLSM Subnetting Examples and Calculation Explained
Subnet Calculator
Software & Windows Solutions - Subnet and IP Calculator One of the most important tools in the belt of a junior network engineer is an IP network calculator. These can be used
The TCP/IP Guide - IP Variable Length Subnet Masking (VLSM)