Question $7$

$($i$)$ A campus has been allocated the $163\mathrm{.}120.\frac{0\mathrm{.}0}{16}$ class B network address space. It is necessary to support maximum $950$ hosts per subnet and accommodate the maximum number of subnets possible. Find the subnet mask which should be used, and the number of subnets supported by this mask.

$($ii$)$ Explain what are advantages and disadvantages of CIDR. Compare the router's operation in networks with and without CIDR.

$($iii$)$ Using the CIDR addressing scheme, a network within a larger network has been allocated a block of addresses which in the dotted decimal representation is $210\mathrm{.}48\mathrm{.}48\mathrm{.}0/20.$ Determine the lowest and highest address in the block $($expressed in dotted decimal notation$)$ and the total number of addresses in the network.

$($iv$)$ A CIDR router contains in its routing table the mask $M=255\mathrm{.}255\mathrm{.}224\mathrm{.}0$ and the base address $BA=123\mathrm{.}88\mathrm{.}160\mathrm{.}0$ of the corresponding attached network. A packet with the destination address $P=123\mathrm{.}88\mathrm{.}223\mathrm{.}148$ arrives at the router. Will the router forward this packet to the attached network? Explain why.