|1:||What is the size in bits of the IPv4 address scheme?|
|A1:||Answer: IPv4 is based on a 32-bit address scheme.|
|2:||Which classes of IPv4 addresses are not considered globally unique unicast IP addresses?|
|A2:||Answer: Class D (multicast) and Class E (experimental) are not used as globally unique unicast IP addresses by hosts and routers on the Internet. Although the private addresses are within the range of unicast addresses, they must not be considered globally unique, because many organizations use them inside their network only.|
|3:||What is the main rationale behind IPv6?|
The IPv4 address scheme is limited by being 32-bit.
Some parts of the address scheme cannot be used as globally unique unicast addresses (Class D, Class E, loopback, ...