$1.$ What is subnetting?

$2.$ What is the organizational motivation for subnetting?

$3.$ In large organizations, what are some disadvantages with allocating IP addresses on a first$-$come, first$-$served basis?

$4.$ How do you determine the number of subnets needed in an organization?

$5.$ What are the three IP addresses on any network that are not available for allocation to hosts?

$6.$ What factors determine the subnet structure of an organization? For example, if you have a Class B address, how will you determine if you should have $512$ subnets, $256$ subnets, $128$ subnets, $64$ subnets, or some other number of subnets?

$7.$ Why are subnet masks needed?

$8.$ What do the $1$s and $0$s in a subnet mask represent?

$9.$ Can $255\mathrm{.}255\mathrm{.}253\mathrm{.}0$ be a subnet mask? Why or why not?

$10.$ What information about a network can be gathered by looking at its subnet mask?

$11.$ How is subnetting in IPv$6$ different from subnetting in IPv$4?$

$12.$ How can subnetting help limit network traffic at routers?