IPv6 Structure and Subnetting

Each member of a group required to individually conduct a research and write a report IPv6 subnetting and routing characteristics. Not more than 2000 words.

Explain IPv6 structure and subnetting.

Explain different IPv6 routing mechanisms, e.g. stationary nodes to mobile nodes, mobile nodes to mobile nodes and stationary nodes to stationary nodes.

Table pros and cons of different routing mechanisms in IPv6-enabled networks.

The purpose of the report is to highlight the process and the concept of IPV6 subnetting and routing. IPv6 can be described as a set of specifications and is developed as an up-gradation of IP version 4 which is IPv4. Therefore the basic structure of IPv6 is quite similar to IPv4 with certain much needed variations. As an improvement from its previous version, the bit length is increased in IPv6 so that more addresses can be stored. This IP version further supports the feature of auto configuration and increased security features that makes it more advanced (Czyz et al., 2014). The report discusses the structure and process of subnetting and further sheds light on the different routing mechanisms of IPv6. The pros and cons of each routing protocols are discussed in the following paragraphs.

IPv6 or Internet Protocol Version is an internet protocol that is mainly used for carrying a data in form of packets from a source to destination. This mechanism is an enhanced version of IPv4 and it has the capability of supporting a large number of nodes in comparison to that of IPv4. IPv6 allows 2128 possible nodes, addresses and combinations. IPv6 was released in June 6, 2012 and was developed in hexadecimal format. IPv6 mainly functions or address broadcasting but does not contain broadcast addresses in any class. It is the most recent version of internet protocol.

An IPv6 address is 128 bits long. An IPv6 header is of fixed length that is 40 bytes. The source and destination address make use 16 bytes which leaves only 8 bytes for general header information (Wu et al., 2014). Therefore, it can be said that the IPv6 header is comparatively simple in comparison to IPv4 and thus it allows more efficient processing of information. One of the significant advantages of IPv6 over IPv4 is that, it offers larger address space of 128 bits and therefore has space for 2¹²⁸ addresses.

An IPv6 address mainly makes use of 128 bits to represent an address. This address includes bits that can be used in subnetting. The picture below represents the structure of a IPv6 subnet.

IPv6 Routing Mechanism

Figure 1: Representing IPv6 subnet

The 16 bits of the subnet is actually equivalent to the IPv4’s Class B Network. The IPv6 subnetting is similar to the concept of variable length subnet masking that is followed in IPv4. In IPv6 subnet masking, 128 bits is reduced to 32 hex digits. The addressing model of IPV6 consists of Unicast, Anycast and multicast. A full length subnet mask of IPv6 makes use of the same 8nhex word format as followed in IPv6 address. The first 48 bits of IPv6 are for internet routing and each IPv6 address is represented by eight groups of four hexadecimal digits. The eight groups are generally separated by colons. An example of an IPv6 subnet mask is 2001:0db8:2231:aaec:0000:0000:4a4a:2100. With IPv6, every device is able to create a unique local address based on MAC address of a particular device. The IPv6 is generally written in a certain way so that the interpretation of the address becomes faster and easier.

One of the significant benefits of making use of  IPv6 is that it provides a flexible routing mechanism. IPv6 allows a much flexible addressing in comparison to IPv4 thus reducing the size of a routing table. In this mechanism, the intermediate routers must have a track of the local portion of their network thus providing the messages appropriately. For this, appropriate neighbor discovery is essential (Lee et al., 2013). In this process, the IPv6 neighbor discovery includes router advertisement, router solicitation, neighbor solicitation, neighbor advertisement and redirect. IPv6 routing protocols make use of longest match prefix. The routing protocols that is supported by IPv6 include RIPng (RIP New Generation), OSPFv3, EIGRP for IPv6, IS-IS for IPv6 andMP-BGP4 (Multiprotocol BGP-4).

The different types of routing mechanism include, routing of stationary nodes to mobile nodes, mobile nodes to mobile nodes and stationary nodes to stationary nodes. In routing from stationary nodes to mobile nodes, the data packets are routed from source to destination using conventional TCP/IP protocols (Carpenter & Jiang, 2013). In this case the mobile node is generally restricted to its home network so that the routing is easier. The other correspondent node is mainly kept stationary in this case.

The mobile to mobile routing on the other hand incorporates different process such as encapsulation methods and broad cast methods. Since both the points are mobile, it becomes necessary to follow these methods. In encapsulation method, the both the nodes are available for the process of encapsulation (Carpenter & Jiang, 2013). Each mobile node is then identified by two IP addresses one of which is home address while other is its care of address. The home address is considered to the permanent IP address and it helps in identifying a mobile node regardless of its location. However, in mobile to mobile node routing, the care of address is changed at each new point and attachment which provides information about the current situation of the mobile node. This routing protocol mainly makes use of Ipv6 neighborhood discovery in order to get the care of address (Hinden, 2017). In mobile to mobile routing, it is necessary to keep at least one home agent configured. For mobile to mobile node routing a node must acquire a care of address which should be used during the time when the mobile node is under the location of a visited network. 

Pros and Cons of Routing Mechanisms

The stationary to stationary routing in IPv6, is configured in the same way in IPv4. In this routing protocol a router is needed to be determining the link local address of each of the neighboring routers, which is needed for establishing a connection (Hinds, Atojoko & Zhu, 2013). In stationary to stationary nodes routing, it is essential to specify the next hop router’s address by making use of link local addresses of the router. The routers are configured with IPv6 route.

All the IPv6 routing mechanisms provide certain benefits, which are efficiency, flexibility, reactivity and easier bug detection (Carpenter & Jiang, 2013). The routing protocol allows the addresses belonging to the same destination to be transported with the help of a single message.

There are a number of advantages and disadvantages of each routing mechanism associated with IPv6. The advantages and disadvantages of each of these mechanisms are discussed in the following table.

Conclusion

The report gives an idea of the structure of IPv6 and the process of IPV6 subnetting. The IPv6 is a next generation internet protocol which is developed as a substitute of IPv4. The report further discusses the routing mechanism of IPv6 and one of the significant benefits of this protocol is that it provides the flexibility in routing. The IPv6 protocol is quite similar to IPv4. The pros and cons of different routing mechanism are discussed in the report. The different IPv6 routing mechanism that is discussed in the report includes stationary to mobile nodes, mobile nodes to mobile nodes and stationary nodes. Therefore IPv6 can be considered as a powerful enhancement of IPv4 with larger address space, a much simplified header and supporting security feature. There are a number of advantages and disadvantages associated with the routing of stationary to stationary routing, mobile to mobile routing and stationary to mobile routing which is discussed in the report 

References 

Carpenter, B., & Jiang, S. (2013). Transmission and Processing of IPv6 Extension Headers (No. RFC 7045).

Czyz, J., Allman, M., Zhang, J., Iekel-Johnson, S., Osterweil, E., & Bailey, M. (2014, August). Measuring ipv6 adoption. In ACM SIGCOMM Computer Communication Review (Vol. 44, No. 4, pp. 87-98). ACM.

Hinden, R. (2017). Internet protocol, version 6 (IPv6) specification.

Hinds, A., Atojoko, A., & Zhu, S. Y. (2013). Evaluation of OSPF and EIGRP routing protocols for ipv6. International Journal of Future Computer and Communication, 2(4), 287.

Lee, J. H., Bonnin, J. M., You, I., & Chung, T. M. (2013). Comparative handover performance analysis of IPv6 mobility management protocols. IEEE Transactions on Industrial Electronics, 60(3), 1077-1088.

Medhi, D., & Ramasamy, K. (2017). Network routing: algorithms, protocols, and architectures. Morgan Kaufmann.

Wu, P., Cui, Y., Wu, J., Liu, J., & Metz, C. (2013). Transition from IPv4 to IPv6: A state-of-the-art survey. IEEE Communications Surveys & Tutorials, 15(3), 1407-1424