A medium sized organization is allocated the IP address block $172\mathrm{.}28\mathrm{.}64\mathrm{.}0/26($in CIDR notation$).$ Explain its type of IP address. Also solve the following: a$)$ Determine the range of IP addresses for the given block. b$)$ If one of the addresses in the block is $172\mathrm{.}28\mathrm{.}64\mathrm{.}35/28,$ calculate the network address