PROBLEMS

$(14\mathrm{.}17)$ In classless interdomain routing $($CIDR$)$ notation, the number of $1$ bits in the mask is appended to the address preceded by a forward slash. If one of the addresses of a subnet is $255\mathrm{.}230.\frac{64\mathrm{.}47}{26},$ what are the first and the last address of that subnet?

$(14\mathrm{.}18)$ A block of addresses is granted to an organization. The last address of the block is $202\mathrm{.}166\mathrm{.}100\mathrm{.}159/27.$ What is the first address of the block? How many addresses have been granted?

$(14\mathrm{.}19)$ A service provider has been granted a block of addresses starting from $180\mathrm{.}150\mathrm{.}0\mathrm{.}0/17.$ The provider needs to distribute these addresses in three groups as stated below:

The first group has $64$ subnets; each subnet needs $256$ addresses.

The second group has $64$ subnets; each needs $128$ addresses.

The third group has $128$ subnets; each needs $32$ addresses.

How many addresses are granted to the provider? How can the blocks of addresses be alloted to each group? How many unused addresses are there?