Similarities and Differences between IPv4 and IPv6 - Literature review Example

?Similarities and differences between IPv4 and IPv6 and why IPv6 has not been implemented on the internet Over the recent years, there has been an increase in the access and use of the internet. This has necessitated the development of communication protocols that address hosts and routing packets or datagrams from source host to the final destination host across internet protocol (IP) networks. The internet protocol (IP) is the main communication protocol used for relaying packets or datagrams across an internetwork through the use of Internet Protocol Suite. Since it is responsible for routing datagrams across network boundaries, the IP is the principal protocol that establishes the internet. It delivers datagrams or packets from the source to the destination host by only basing on their addresses. Over the years, the IP has undergone revisions in its development and the Internet Protocol version 4 (IPv4) is its 4th revision. Another recent revision is the Internet Protocol version 6 (IPv6). Both IPv4 and IPv6 are at the core of internet internetworking methods that are standards-based. However, there exist differences between the two versions of the IP as well as their levels of deployment. Since its development, the IPv4 is the first version of the internet protocol to be widely deployed and until today, it is still stands out as the Internet Layer protocol that is widely deployed. This is so despite the development of more advanced version of the IP, the IPv6. This is an indication that there is something about the IPv4 that makes it more popular than the IPv6. I choose this topic with an aim of knowing the differences and similarities that exist between the IPv4 and IPv6 so as to identify why IPv6 has not been implemented on the internet. Identification and definition of the problem As noted in the above discussion, the IPv4 is the first version of the internet protocol to be widely deployed and it is still stands out as the Internet Layer protocol that is widely deployed. However, the IPv6 was designed to succeed this version of the IP. For example, the IPv6 implements some features that are not present in the IPv4. According to Fahmida (2011), the IPv6 was designed by the internet engineering task force (IETF) with an aim of dealing with the IPv4 address exhaustion that has been anticipated for long. From these, it is expected that IPv6 should have achieved a greater level of deployment than the IPv4. But as it is, the deployment of IPv6 is still at its infancy. This paper analyses the reasons as to why IPv6 has not been implemented on the internet. Literature Review In order to identify the reasons as to why IPv6 has not been implemented on the internet, it is important to understand the similarities and differences between IPv4 and IPv6. This will be important in identifying any weaknesses that underlie the IPv6 and provide a base for making recommendations for improvements that will enable it to achieve a good level of deployment. For this paper, the sources of the literature review and analysis will be books, journals and articles on computer sciences and information technology. credible online sources on the same will also be used. Similarities Both IPv4 and IPv6 are internal layer protocols designed for packet-switched internetworking. The two IP versions are also capable of providing end-to-end datagram or packet transmission across more than one IP networks. In terms of the structure of their packets, both the headers of IPv4 and IPv6 have an optional fields or extension that can be used to implement special features. Differences According to (Shankland, 2011), IPv4 allows 32 bits for an IP and because of this, it can support 232 (4,294,967,296) addresses. On the other hand, IPv6 uses 128-bit addresses, therefore, the developed address space supports 2128. This is about 340 undecillion or 3.4?1038 addresses. This makes the large address space an important feature of IPv6 over IPv4. This expansion creates room for more devices and users on the internet. It also allows for additional flexibility in allocating addresses and increases efficiency for routing traffic. In addition to these, the expansion eliminates the necessity for network address translation (NAT). NAT managed to get widespread deployment in an effort to deal with IPv4 address exhaustion. The addresses for IPv6 are well allocated whereas those of IPv4 are poorly allocated with only about 14% of all addresses that are available being utilised (Shankland, 2011). The long IPv6 addresses make the allocation of addresses to be simple, allow implementation of special and more advanced addressing features and allow efficient route aggregation. Although the utilisation of the actual address space will be small in IPv6, its routine efficiency and network management is improved by hierarchical route aggregation and the large subnet space. IPv6 implements some features that are not found in IPv4. For example, it makes aspects of address assignment and network renumbering to be simple. This also extends to router announcements when shifting from one internet connectivity providers to another (Deering and Hinden, 1998). Unlike the IPv4 subnet, the size of the IPv6 subnet has been has been standardized. This has been achieved through the fixing the host identifier portion of an IP address to 64 bits. This has been done in order to facilitate an automatic mechanism for developing the host identifier from the Media Access Control address (MAC address) or media addressing information of the of the lowest layer in the IP Suite addressing information, also known as the link layer. Other advancements of IPv6 that differentiates it from IPv4 include the integration of network security into the design of its architecture. The specifications of the IPv6 mandate the support for IPsec as a very important interoperability requirement. IPv6 is different from IPv4 in that it specifies a new packet format, a format that is specifically designed to reduce packet header processing by means of routers (Deering and Hinden, 1998). This makes the headers of the two IP versions to be significantly different hence the IPv6 and IPv4 are not inter-operable. The difference between IPv4 and IPv6 in terms of packet headers is that the packet headers for IPv6 together with the process forwarding have both been simplified. Although the size of the packet headers for IPv6 are twice those of IPv4, the IPv6 packet processing by routers is more efficient. Unlike IPv4, a lot of fields that are rarely used are normally moved to a separate optional header in Ipv6. The routers of IPv4 perform fragmentation whereas those of IPv6 do not. The IPv6 hosts have an option of either performing end-to-end fragmentation, path MTU discovery, or to send packets whose size not bigger than the MTU size of 1280 octets. The end-to-end fragmentation means that unlike the IPv4, IPv6 can only handle fragmentation in the ends of a communication session (Partridge and Kastenholz, 1994). There exist differences between Ipv4 and IPv6 in terms of mobility. Mobile IPv6 evades triangular routing hence they are as efficient as native IPv6. This is unlike mobile IPv4. Shankland (2011) points out that unlike IPv4 routers, the routers of IPv6 may support network mobility and this enables the entire subnets to shift to another router connection point without having to undergo renumbering. There are also differences in the packet structure if IPv4 and IPv6. Partridge and Kastenholz (1994) state that although the IP packets for the two IP versions are composed of two parts, the packet header for IPv4 consists of 14 fields, this is not the case for IPv6. Out of these, 13 fields are required while the 14th one is optional and is aptly named. The header packet for IPv6 is composed of a fixed option with very little functionality required for all packets. This means the IPv6 has a fixed length header unlike IPv4. Discussion and Analysis of the Problem From the above discussion, the IPv6 is such an ideal IPv6 due to its advancements over the IPv4. However, there are some features of the IPv6 that have made it not to be implemented on the internet. Although IPv6 is supported on all main operating systems that are currently in use in business, commercial and home customer environments, it does not implement interoperability features with the existing IPv4. Essentially, this creates the parallel, independent network. The problem with having two networks that are parallel and independent is that exchanging traffic between them creates the need for special translator gateways. However, the existing computer operating systems normally implement dual-protocol software to facilitate transparent access to the two networks. They do this natively or through the use of tunnelling protocol such Teredo, 6to4 or 6in4. Due to these complications related to the use of IPv6 as a Standards Track protocol marked its 12th anniversary yet contrastingly, its general worldwide deployment was in its infancy. A study conducted by Google Inc in 2008 indicated that at the time, the implementation or penetration of IPv6 was below 1% of internet-enabled hosts in any country (Shankland, 2011). Solution and Recommendation There is an exhaustion of IPv4 addresses and therefore we cannot avoid a transition to IPv6. Information from Asia-Pacific Network Information Centre (2011) reveal that on 3rd February, 2011, the Internet Assigned Numbers Authority (IANA) officially assigned the last batch of IPv4 5/8 address internet registries of various regions of the globe. This officially exhausted the global pool of blocks of addresses that are completely fresh. One of the solutions to the minimal implementation of IPv6 is to make changes to the design of IPv6 that are important in reducing the internal differences between it and IPv4. This will allow the functionalities in the IPv6 stack that are available to programmers to work the same as the IPv4 mapped addresses. There is also a need to increase the efficiency of tunnelling. Tunnelling is the technology that enables an isolated network or host to reach the IPv6 internet. In order to reach this internet, one must use existing infrastructure of IPv4 to carry IPv6 packets and tunnelling facilitates this successfully. Tunnelling involves the encapsulation of IPv6 packets within the version 4 of the IP and in effect, IPv4 acts as a link layer for IPv6. The tunnelling process should also be automated to ensure that IPv6 automatically determines the IP4v4 tunnel endpoints. It has been noted that compatibility with IPv6 networking is the main firmware or software issue surrounding the IPv6. Therefore, a large percentage of the older hardware should therefore be replaced instead of upgrading them. This is because in some cases, the updating their software is not possible or the manufacturer no longer exists. When the weak points of the IPv6 have been substantially, a good level of its implementation should be sought. This is can be done through the preparation of internet servers be to serve only IPv6 clients by January 2012. Almost all personal computers running the latest versions of the operating system are ready for IPv6. In these personal computers, a high percentage of applications that are popular and have network capabilities ready. It will therefore be very helpful if the developers of personal computers would work towards upgrading these applications. This will increase the level of reception or compatibility with the IPv6. All equipments that are in the process of manufacturing or are to be manufactured should be fitted with larger storage and memory space that will accommodate the new IPv6 stack. This means manufactures should will to spend finances on software development so as to release equipments that are IPv6-ready. Conclusion IPv6 was designed to deal with the problems of IPv4. However, there are more differences than similarities between IPv4 and IPv6. The architecture of IPV6 has been developed with advancements and its special feature is the large address capacity over the IPv4 and this brings along some advantages. These include creation of room for more devices and users on the internet, allowing for additional flexibility in allocating addresses and increased efficiency for routing traffic. Other differences between IPv4 and IPv6 are seen in the packet structure where IPv6 has a fixed length header while IPv4 does not. One major problem with the IPv6 is that it does not implement interoperability features with the existing IPv4 and this essentially this creates the need for a parallel, independent network. This is one of the main reasons why it has not been greatly deployed compared to the IPv4. Despite the differences that exist between IPv6 and IPv4, IPv6 is basically a conservative extension of IPv4. Most application-layer and transport protocols need minimal or no change to operate over IPv6 with the exception of FTP and NTPv3. References Asia-Pacific Network Information Centre (2011). “APNIC IPv4 Address Pool Reaches Final /8.”Online\; http://www.apnic.net/publications/news/2011/delegation. Deering Hinden, R. (1998). Internet Protocol, Version 6 (IPv6) Specification. RFC 2460. Online: http://tools.ietf.org/html/rfc2460. Fahmida, R. (2011). “IPv4 Address Depletion Adds Momentum to IPv6 Transition.” Online: http://www.eweek.com/c/a/IT-Infrastructure/IPv4-Address-Depletion-Adds-Momentum-to-IPv6-Transition-875751/. Partridge, C.and Kastenholz, F. (1994). Technical Criteria for Choosing IP The Next Generation (IPng). RFC 1726. Online: http://tools.ietf.org/html/rfc1726. Shankland, S. (2011). Moving to IPv6: Now for the hard part (FAQ). 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