[okwo Ifeanyi Ogene]

IPv4 has lasted for a long time due to its initial design, which seemed to provide a large number of addresses, as well as mitigating technologies like Classless Inter-Domain Routing(CIDR) and Network Address Translation(NAT) that have prolonged its use. However, it is not sustainable because the number of unique IPv4 addresses is limited to about 4.3 billion, which is insufficient to meet the demands of a rapidly growing number of internet users and devices.