CIDR and VLSM Comparison
CIDR and VLSM are similar.
CIDR allows for the efficient routing mechanism to take place by the ability of the recursive allocation of an address block.
Routing is based on the address block allocation and not the individual Class address.
VLSM permits recursion at will but more so on an individual address space in use by the customer.
VLSM allows for variable lengths based on a Class address assigned by an ISP.