How Internet Protocol Works

Published Date: 02 Nov 2017

In 1970s, the Internet Protocol version 4 was developed and in 1981 the main protocol standard that governs IPv4 functionality was published. India and China are population dense countries which one of the smallest reason to cause never known expansion of Internet usage in recent years. Due to the continuous usage of the Internet run on IPv4, impending shortage of address space was recognized in the year 1992. Predicting the future for Internet usage, the Internet Engineering Task Force (IETF) begins the process in 1994. Since then, over 30 IPv6 RFCs have been published (Das, n.d.).

Internet Protocol Version 6 (IPv6) is the design and improvement of a suite of standards and protocols. IPv6 is a worthy tool to replace IPv4 over the upcoming years. There is an increase of sorts in the number and series of IP capable devices which are being released and the increasingly tech savvy global population usage. The aim of the new protocol is to effectively support expanding internet usage, functionality and address security concerns. 32-bit system is used by IPv4 however IPv6 uses a 128-bit size and will allow 3.4x1038 possible addresses which is enough to cover every resident on the planet earth several times over (Das, n.d.).

3. How Internet Protocol works

Frame relay Wide Area Network (WAN) interconnects with two Local Area Networks (LANs). The end system must share the same protocols. Moreover, both end systems and routers must share a common Internet Protocol. After which, the IP attaches a header specifying the global internet address of the end host. This address is contained in two parts which are end system identifier and network identifier. The combination of IP header is named as datagram. This datagram is than being encapsulated with the LAN protocol and sent to the router, which strips the LAN fields in order to read the IP header. After this process, router will be encapsulate the datagram with the frame relay protocol fields and transmits to another router across the WAN. The last process datagram is being recovered by stripping off the frame relay fields, which it then wraps in LAN fields (Stallings, W, 2007, p. 540).

4. Basic Introduction to IPv4

The key function of network layer protocols is addressing. Addressing allow data communication between hosts on the same network or on different network. Internet Protocol version 4 (IPv4), gives hierarchical addressing for packet that carry your data (Dye, M.A., Mcdonald, R., & Rufi, A.W., 2011, p. 173).

IPv4 is the version’s first protocol to be extremely deployed and in the progress of the IP, it is the fourth revision. By far, IPv4 is still the most extremely deployed Internet layer protocol. IPv4 is a connectionless protocol, used on packet-switch Link Layer networks. It works on a best effort delivery model and in that it does not guarantee delivery, or does it promise proper avoidance of duplicate delivery or sequencing (Surya, January 2006).

5. Disadvantages of IPv4

Limited address space is the most urgent and visible obstruction with using IPv4 on the modern Internet which seriously decrease in public addresses. Public IPv4 addresses are becoming scarce, due to the initial address class division practices of the early Internet. Most public IPv4 address space worldwide is held by organizations in the United States. Due to limited address space, Network Address Translators (NATs) have to share IPv4 public address among several privately addressed hosts. Where, NATs act as a barrier for server and add complexity to global network (Safari, n.d.).

Second disadvantage is flat routing infrastructure. Address prefixes were not allocated to create a hierarchical routing infrastructure, in the early internet. Instead, individual address prefixes were assigned and this address prefix became a new path of the internet backbone routers in the routing table. Internet today is a mixture of hierarchical and flat routing. However, in the routing tables of internet backbone routers there are still more than 85 00 routes (Safari, n.d.).

Third is configuration. IPv4 must be arranged in a particular form, either through the Dynamic Host Configuration Protocol (DHCP) or manually. DHCP allow IPv4 alignment administration to scale to large networks however users must also configure and able to cope with a DHCP infrastructure (Safari, n.d.).

Fourth would be security. IPv4 is Identify clearly and definitely with the usage of Internet Protocol Security (IPsec). In contrast, IPsec is a choice for IPv4 implementation. Nowadays, built-in security is very important because an application cannot rely on IPsec to secure traffic as an application might switch to other security standard or security scheme. In addition, built in security is required because of increasingly hostile environment on the internet (Safari, n.d.).

Fifth is prioritized deliver. IPv4 specially hands parameters for low variance and low delay in delay for video or voice traffic. However, it relies on Type of Service (TOS) field in IPv4, which is not supported by all the devices on the network. Moreover, detection of the packet flow must be made using an upper layer protocol like User Datagram Protocol (UDP) or TCP. This extra processing of the packet by intermediate routers causes forwarding less efficient (Safari, n.d.)

Last disadvantage is mobility. Internet connected devices newly requires mobility, in which a node could change its address as it changes it’s physical connection to the internet and still uphold current connections. Even though there is specification for IPv4 mobility, because of its lack of infrastructure, communication with IPv4 mobile node are inefficient (Techno, 2009)

6. Basic information about IPv6

IPvs6 stands for Internet Protocol Version 6, for internet it is the next generation protocol. It is designed to replace Internet Protocol Version 4 (IPv4) and provide several advantages. Both IPv6 and IPv4 explain the network layer protocol on how data is sent from one host to another over packet switched networks. Importantly, IPv6 stores addressing and control information to direct packets for the next generation Internet. Moreover, IPv6 is documented in several Request for Comments (RFCs) starting from RFC 2460. IPv6 is the successor of IPv4 however in the upcoming years, both protocol versions will be data oriented protocols for the Internet (useipv6, n.d.).

Why IPv6? As it address the main problem of IPv4. One of the main note is IPv6 has a very large address space. With the help of IPv6 addressing scheme, a substantial rise in number of hosts that can be addressed. Moreover, this addressing scheme will also remove the need of Network Address Translation (NAT) which causes several networking problems. Besides that, IPv6 brings in Quality of Service (QOS) which is required for several new applications like video, interactive games and IP telephony. Where, IPv4 is a best effort service, while IPv6 ensures QOS, while transporting traffic over the network, it delivers performance guarantee. Moreover IPv6 has a 20 bit flow label and provides a traffic class field (8 bits), in order to implement QOS marketing (Goscomb, n.d.)

Mobile IPv6 characteristic ensures transport layer connection survivability and permits a host to remain within reach in any case of its position in an IPv6 network and also ensures transport layer connection survivability. Even though the mobile node changes addresses and locations, the connections which the mobile node is being communicated are maintained with the help of Mobile IPv6. In addition, the mobile node is always reachable because the connections to mobile nodes are formed with a specific address that is always designated to the mobile node (Goscomb, n.d.).

7. Advantages of IPv6

There are several more advantages in IPv6, besides the usage of 128 bit size. Advantages such as more efficient routing, more efficient packet processing, directed data flows, simplifies network configuration, support for new service and security (Levy, 2011)

Firstly, the size of routing tables is reduced by IPv6 and also creates routing more hierarchical and efficient. IPv6 permits ISPs to combine the customers’ networks prefixes into a single prefix and publicize this one prefix to the IPv6 internet. Moreover, in IPv6 networks, rather than the router, fragmentation is handled by the source, using protocol for innovation of the route’s maximum transmission unit (Levy, 2011).

Secondly, Packet processing is more efficient with IPv6’s simplified packet header. Compared to IPv4, IPv6 stores no IP level checksum, which means at every routers hop, the checksum doesn’t need to be recalculated. Most link layer technologies already stores checksum and error-control capabilities, which made possible of getting rid of the IP level checksum. Moreover, most transport layers have a checksum that enables error detection, which handle end to end connectivity (Levy, 2011).

Thirdly, Rather than broadcast, IPv6 supports multicast. Multicast allows bandwidth intensive packet flows to be sent to multiple destinations continuously, saving network bandwidth. Disinterested hosts no longer have to process broadcast packets. Moreover, the IPv6 header consists of a new field, named flow label, which can recognize packets fitting in to the same flow (Levy, 2011).

Moreover, IPv6 has built in address auto configuration. Where, in the router advertisement router will transmit the prefix of the local link. By appending its link layer address, host can generate its own IP address, reformed into Extended Universal Identifier (EUI) 64 bit format and the 64 bits of the local link prefix (Levy, 2011).

In addition, throughout connectivity at the IP layer is rebuilt by eliminating Network address Translation (NAT), which enables new and valuable services. One to one networks are easier to create and maintain, services such as Quality of Service (QOS) and VoIP become stronger (Levy, 2011).

Lastly, IPv6 consist of IPsec, which provides authentication, confidentiality and data integrity. Due to their potential to carry malware, corporate firewalls block IPv4 ICMP packets, but the Implementation of the Internet Control Message for IPv6 (ICMPv6), have chances of getting permitted as IPsec can be stored to the ICMPv6 packets (Levy, 2011).

8. Difference between IPv4 and IPv6

IPv4 and IPv6 have differences in addresses, address configuration, ICMP, IPv6 packet structure and multicast. In addresses, IPv6 IP addresses are 128 bits long which is too long to remember but IPv4 addresses are only 32 bits. The analogy for this would be, all IPv4 addresses would fit into a golf ball however all of the IPv6 addresses would fill the sun. That is the address size difference between this two (gogo6, n.d.).

Address configuration, both state full and stateless address configuration functionality is provided by IPv6. DHCP functionality in IPv4 is similar to state full address configuration. Stateless Address Auto Configuration (SLAAC) is also supported by IPv6. In this manner, by generating a local IP address can automatically configure their network configuration. Helps locating a default router, locating neighbours on the same local segment and usage of prefix forthcoming by the router through ICMP messages to generate a global routable address without any user interaction (gogo6, n.d.).

ICMP, In IPv4 basic ICMP messages is found but IPv6 have taken in numerous new ICMP messages, which is a crucial component in IPv6. Replacement made on ARP functionality in IPv4 with Neighbour and Router Discovery messages. Fragmentation in IPv6 is not done by intermediate routers but by endpoints only. A packet needs to be fragmented to signal messages, after the original packet is dropped, an ICMP type 2 is sent to the originating host. Therefore, to avoid breaking fragmentation, ICMP type 2 packets need to be permitted into the network, including messages from external addresses. Moreover, fragmentation would not be required very often as fragmentation in IPv6 is 1280 octets but fragmentation in IPv4 is 576 octets only. IPv6 is two times more than the previous IPv4 (gogo6, n.d.).

IPv6 packet structure, One of the changes which are not that obvious is the packet header in IPv6. The basic IPv6 header has been designed to only contain the following fields, which are traffic class, payload length, hop limit version, flow label, destination address and source address. Where, routers could process the streamlines header more efficiently. Let’s take flow label for example, it efficiently identify packets that fit in to the same connection. Where, routers will have access to information when traversing the multiple extension headers which will be current in a typical IPv6 packet, by placing flow label in the header (gogo6, n.d.).

Multicast, even though multicast allows sending a single packet, it still communicates with multiple systems on the network. IPv6 multicast takes much more prominent role than IPv4, even when it can employ multicast. IPv6 does not contain a broadcast address. Moreover, multicast is used in several ways for communication through specific device groups, such as all hosts and all routers on the local network. In addition, ICMP messages to these multicast groups allow IPv6’s Neighbou Discovery to operate efficiently. Overall, the multiplied reliance on multicast goes together with increased dependence on ICMP (gogo6, n.d.).

9. IPv6 Header

IPv6 header is longer than the IPv4’s header, IPv6 contains only 8 fields however IPv4 contains 12 fields. This means, IPv6 routers have less processing to do per header, which would increase the speed for routing. The IPv6 header consists of the following fields such as Version the value of the Internet Protocol version number is 6. DS/ECN usable by originating nodes for differentiated service and congestion functions. Flow label used by a computer to label those packet which request for special handling by routers within a network. Payload length it is the total length of all the extension headers including the transport level-PDU. Next header after the IPv6 header it notifies the type of header needed, it will either be a higher layer header or extension header. Hop limit helps to prevent packets continuously circulating on an IPv6 internetwork, moreover its function is to decrease hop limit by one and discard the IPv6 packet when the hop limit reaches 0, this only occurs when forwarding an IPv6 packet (Server, 2005). Source address is the originator of the packet’s address (Stallings, W, 2007, p. 560). Destination address contains the address of the receiver of the packet (Stallings, W, 2007, p. 561).

10. IPv6 addresses type

Let’s look into the three various types of IPv6 addressing. IPv4 we have unicast, broadcast and multicast addresses. In IPv6 it has unicast, multicast and anycast. The broadcast addressed are not used anymore in IPv6 because they are changed with multicast addressing (Schroder, 2006)

IPv6 unicast is alike to the IPv4’s unicast address, a single address recognizing a single interface. A Unicast address contains four types which are global unicast, Link local, Unique local and Special addressed. Global unicast are conventional and publicly routable address. Link local addresses mean setting up a permanent small Local area network the easy way and are not meant to be routed, but restrained to a single network segment. Unique local addresses is similar to Link local meant for private addressing but with the addition of being unique, which doesn’t cause address collisions when joining two subnets. Special addresses are loopback addresses (Schroder, 2006).

IPv6 multicast is similar to old IPv4 broadcast address, every interface in a group is delivered with a multicast address. The only difference is, IPv6 is targeted rather than annoying every single computer on the segment with broadcast blather, which means only host who are participant of the multicast company gets the multicast packets. Multicast in IPv6 is routable and routers will forward multicast packets only if the members in multicast groups also forward the packets (Schroder, 2006).

Any cast address is a single address appointed to multiple nodes. To the first available node, anycast is being delivered. This is an easy way to provide both automatic failover and loading balancing (Schroder, 2006).

11. IPv6 usage

Support for IPv6 has gone up but most website still use IPv4, even though Internet protocol addresses are running out. Domains such as .com, .net and .org are supported IPv6 more. In order to switch fully to IPv6, enterprises and service providers require IPv6 communication fully, however it is expensive for them to afford. So, dual software stacks are being used but it still depends on IPv4 addresses. One of the world’s largest domain registers is "GoDaddy", which has over thirty million customers and planning to extend its IPv6 usage to support its new protocol. Overall, it said to be the usage for IPv6 is still very little (Lawson, 2011).

IPv6 is running over a decade however major companies like Google and Microsoft yet to use IPv6. People accept that Internet Protocol addresses are running out, at the same time they believe that changing to new addressing scheme is not a perfect solution. It appears to be, all prefer IPv4, as it is cheaper compared to IPv6 usage. Moreover technologies like NAT allows user to share IP addresses or they could purchase a single IP address from those who have more than they need (Lee, 2008)

According to a survey, it says that cost of IPv6 deployment overall cost is to be approximately six percentage of an average company's overall Information technology budget. They also accept that change to new addressing scheme is a must needed measure now however it suspect that IPv6 will force business to consider other infrastructure measurement and reduce performance on servers (Lanshack, n.d.).

12. Conclusion

To summarize, IPv6 was created to replace IPv4 due to reducing number of Internet Protocol addresses. However, IPv6 is still in the market for over ten years and the usage still seems to be very low compared to IPv4. Beside, plenty addresses space benefits which IPv6 has. The main highlight of IPv6 is it holds more advantage than IPv4. But still IPv4 is still being used in most of the areas, it’s due to financial concern and IPv6 still somewhat depend on IPv4 specification. In conclusion, the cost of IPv6 has to be negotiated because the availability of IPv4 addresses are less than twenty percentage and IPv6 holds more advantage which could boost the server’s performance.

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