Internet Dynamics: IPv4 versus IPv6

IP addressing is one the most basic procedures in order to connect in the dynamics of the Internet. IP address is the one responsible for the smooth exchange of data from one PC unit to others. Just like the basic post mail address, our IP address serves as our address for our needed information to reach us.

Below is a table that differenciates IPv4 and IPv6:


IPv4 is the most widely used Internet Protocol in all kinds of communications and connections via obtaining an IP address. However, it has also been viewed to be a limited resource. It is limited to a fixed number of connected addresses of 4,294,967,296. While this is only a theoretical maximum, we cannot expect that all of these will be used efficiently and are still insufficient to connect all devices. With the increased use of the Internet on a global scale, IP addresses are deemed to be running out and the exhaustion is expected to come in the next few years.

The purpose of IPv6 is to increase the available IP addresses. Previously, with the use of IPv4, 32-bit address fields provided about 4 billion unique IP addresses. Now, with the use of IPv6 which has 128-bit header, there are now approximately 3.4 x 1038 addresses. These trillions of IP addresses claimed to be enough to give each person on earth unique IP addresses. The features of IPv6 against IPv4 may be summarized as follows: new header format, larger address space, more efficient and hierarchical addressing and routing infrastructure, built-in security via IPsec, better support for prioritized delivery, a better protocol for neighboring node interaction and greater extensibility.

Hence, IPv6 is expected to replace IPv4 to address this problem. It provides an expanded address space to support new Internet applications that require advanced features to provide various types of services. However, IPv6 is still rarely used. The network performance influences the user experience in many applications and poor performance of IPv6 limits its deployment. Furthermore, because of the wide distribution of IPv4, transition issues can also be considered as critical limiting factors. Hence, although IPv6 will replace IPv4 in the next years, it will be necessary to expect that IPv4 and IPv6 hosts will coexist within the transition procedures between the two protocols: IPv6 to IPv4.

While others believe that Internet users largely shift to IPv6 and IPv4 will disappear soon, the two will continue to coexist because Internet users will shift from one to another based on IP needs.  Even though there is a general consensus that IPv6 is indeed better than that of IPv4, some are not convinced of the benefits offered by IPv6 and still prefer to use the older version. Nevertheless, some of the observed benefits of using IPv6 over IPv4 include increased address space and improved address allocation.

IPv6 is expected to improve address allocation. Compared to IPv4, IPv6 has the additional capability to reform and rationalize the allocation of IP addresses. While IPv4 have allocated a large number of IP addresses in North America, Europe, and Australia, most of these remain unused and some of the allocated ones are not even effectively used and remain inactive. Allocation systems of IPv4 have improved in the recent years but still, it has failed neither prevent warehousing of IP addresses nor to motivate even the large companies to return their unused IP addresses. On the contrary, IPv6 has mechanisms to prevent address warehousing and the inefficient use of IP addresses and IP address blocks.

Dual stacking is seen as an option for maximized inefficiency. The host and router use both IPv4 and IPv6 at the same time. The host has both an IPv4 and IPv6 address. Hence, its IPv4 host can send packets to other IPv4 hosts and its IPv6 host can also send packets to other IPv6 hosts. The router, aside from the addresses provided by the IPv4, it can also configure IPv6 addresses. Hence, it can receive and forward both Ipv4 and IPv6 packets.


The tunnel function of IPv6 packets sent by a host is accepted and encapsulated using the IPv4 packet. The IPv4 packet is forwarded to an existing Ipv4 Internetwork. Afterward, the router then encapsulates or tunnels this packet to the IPv4 header. The destination of the packet is forwarded by any or all the routers. Hence, the two can work complimentary via tunneling.

The goals of IPv6 are basically to support scalability, security, and multimedia transmissions. The address space is increased from 32 bits to 128 bits. Moreover, unlike IPv4, IPSec, as implemented in IPv6, has become a requirement the IPv6 header to add security via encryption and other IPsec security measures. IPsec is one of the leading standards for cryptographically based authentication including integrity and confidentiality services at the IP datagram layer. It ensures the low-level IP packets are continuously transferred between the server and the client with authenticity and privacy and without alteration.

Moreover, fragmentation support has been moved from routers to the sending hosts. The IPv6 header does not include a checksum and only introduces extension headers. Lastly, IPv6 requires no manual configuration or DHCP (Dynamic Host Configuration Protocol) which makes the deployment more comprehensible, feasible and easier.

Cisco compared IPv4 and IPv6 in terms of throughput and latency. It was observed that the two protocols were remarkably similar in throughput and latency. It was only in the smaller packets or 256 bytes and less that the IPv4 showed higher throughput than that of IPv6. These smaller packets are only seen in smaller switching platforms. On the other hand, in the higher packets, the two are identical.

Watch this video to answer “Why do we need to transition from the Internet Protocol that’s served us so well for all these years? Maybe because we’re completely running out of IP addresses”





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