a)
42.68.21.99 = 00101010.01000100.00010101.01100011
1048576 = 2²⁰ (20 Hostanteil -> 12 Netzteil)

Netz:00101010.0100
Host:0100.00010101.01100011

CIDR: 42.64.0.0/12

b)
Netzklassen: 
	A->2²⁴ Hosts
	B->2¹⁶ Hosts
	C->2⁸ Hosts
=> 2²⁰ Hosts -> Klasse A

c)
00101010.01000000.00000000.00000000 => 42.64.0.0 
00101010.01001111.11111111.11111111 => 42.79.255.255
=>  42.64.0.0 - 42.79.255.255 

d)
11111111.11110000.00000000.00000000 => 255.240.0.0
00101010.01001111.11111111.11111111 => 42.79.255.255


