IPv4 structure, CIDR, subnetting, VLSM, supernetting, IPv6, and enterprise address planning — worked with real numbers from the first octet down to the last usable host.
Subnetting is arithmetic, not memorization — every subnet boundary, broadcast address, and summary route in this module follows directly from the same binary relationship between a mask's host bits and the block size it produces. This module works that relationship in full, from converting an address to binary through a complete VLSM allocation across unequal-sized subnets to dividing an IPv6 /48 site allocation into /64s.
By the end of this module you should be able to take a real address block and a real set of host-count requirements and produce a correct, minimally wasteful subnet plan by hand — the same discipline Module 5's VLAN and trunk design and Module 6's routing content both build directly on top of.