Abstract:

In this paper, some mechanisms of IPv4 Variable Length Subnet Mask are mentioned, and a tool for their demonstration and explanation is presented. This tool is a graphical user interface software that allows users to create a table with a given range of IP addresses and show the relation between subnets with different sizes (length of subnet mask or prefix). It also solves cases where given IPv4 spaces have to be efficiently calculated for subnetworks with different sizes. The most useful function is to draw maps and topologies with dynamically assigned IP addresses. This tool allows users to create demo topologies and readdress them in real-time. Despite its primary teaching purpose, it is also a useful tool for network professionals.