Through the years, IPv4 has been updated to address new challenges. However, even with changes, IPv4 still has three major issues:
- IP address depletion - IPv4 has a limited number of unique public IP addresses available. Although there are approximately 4 billion IPv4 addresses, the increasing number of new IP-enabled devices, always-on connections, and the potential growth of less-developed regions have increased the need for more addresses.
- Internet routing table expansion - A routing table is used by routers to make best path determinations. As the number of servers (nodes) connected to the Internet increases, so too does the number of network routes. These IPv4 routes consume a great deal of memory and processor resources on Internet routers.
- Lack of end-to-end connectivity - Network Address Translation (NAT) is a technology commonly implemented within IPv4 networks. NAT provides a way for multiple devices to share a single public IP address. However, because the public IP address is shared, the IP address of an internal network host is hidden. This can be problematic for technologies that require end-to-end connectivity.