08-16-2017, 09:10 PM
IPV4 VS IPV6
Submitted by
Basha.K.M
No:19
S7T2
College Of Engineering, Trivandrum
2007-11 batch
Submitted by
Basha.K.M
No:19
S7T2
College Of Engineering, Trivandrum
2007-11 batch
ABSTRACT:
Internet Protocol version 4 (IPv4) is the fourth revision in the development of the Inernet protocol (IP) and it is the first version of the protocol to be widely deployed. Together with IPV6, it is at the core of standards-based internet working methods of the Internet. IPv4 is still by far the most widely deployed Internet protocol. As of 2010, Ipv6 deployment is still in its infancy. IPv4 is a connectionless protocol for use on packet switched page link networks (e.g. Ethernet). It operates on a best effort delivery model, in that it does not guarantee delivery, nor does it assure proper sequencing or avoidance of duplicate delivery. These aspects, including data integrity, are addressed by an upper layer transport protocol (e.g., Transmission control program).For the next generation very high-speed network, the Telecommunications Advancement Organization (here in after referred to as TAO) has established a gigabit network for research and development. IPv6 (Internet Protocol version 6) is the next generation Internet protocol. Different producers have different IPv6 implementations. IPv6 was designed to meet requirements that did not exist when IPv4 was first conceived. It takes into account many experiences accumulated using IPv4 in the last 20 years. IPv6 is designed to replace IPv4 in the future. As the next generation Internet protocol, IPv6 provides capabilities that go beyond larger addresses. IPv6 and IPv4 are both network layer protocols and play the same role in network architecture. IPv6 is designed based on IPv4 , and IPv6 adopts many new concepts that don t exist in IPv4. IPv6 is in its growing stage in which new protocols are being proposed and more and more IPv6 devices are being produced.
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INTRODUCTION:
The first publicly used version of the Internet Protocol, Version 4 (IPv4), provides an addressing capability of about 4 billion addresses (232). This was deemed sufficient in the early design stages of the Internet when the explosive growth and worldwide proliferation of networks was not anticipated.During the first decade of operation of the Internet, by the late 1980s, it became apparent that methods had to be developed to conserve address space. In the early 1990s, even after the introduction of classless network redesign, it became clear that this would not suffice to prevent IPv4 address exhaustion and that further changes to the Internet infrastructure were needed. By the beginning of 1992, several proposals appeared and by the end of 1992, the IETF announced a call for white papers and the creation of the IP Next Generation (IPng) area of working groups. The Internet Engineering Task Force adopted the IPng model on July 25, 1994, with the formation of several IPng working groups. By 1996, a series of RFCs were released defining Internet Protocol version 6 (IPv6), starting with RFC 1883.The IETF assigned version 6 for the new protocol as a successor to version 4, because version 5 had previously been assigned to an experimental flow-oriented streaming protocol (Internet Stream Protocol), similar to IPv4, intended to support video and audio.It is widely expected that IPv4 will be supported alongside IPv6 for the foreseeable future. IPv4-only nodes are not able to communicate directly with IPv6 nodes and will need assistance from an intermediary gateway or use other transition mechanisms. IPv4 uses 32-bit (four-byte) addresses, which limits the address space to 4,294,967,296 (232) possible unique addresses. However, some are reserved for special purposes such as private networks ( 18 million addresses) or multicast addresses ( 270 million addresses). This reduces the number of addresses that can potentially be allocated for routing on the public Internet. As addresses are being incrementally delegated to end users, an IPv4 address shortage has been developing. However, network addressing architecture redesign via classful network design, Classless Inter-Domain Routing, and network address translation (NAT) has contributed to delay significantly the inevitable exhaustion.This limitation has stimulated the development of IPv6, which is currently in the early stages of deployment, and is the only long-term solution.
IP NETWORK ADDRESSING(IPV4):
INTERNET is the world s largest public data network, doubling in size every nine months.For addressing systems connected to internet ip addressing is used. IPv4 uses 32-bit (four-byte) addresses, which limits the address space to 4,294,967,296 (232) possible unique addresses. They are most often written in dot-decimal notation, which consists of the four octets of the address expressed separately in decimal and separated by periods. The following table shows several representation formats:
Notation Value Conversion from dot-decimal
Dot-decimal notation
192.0.2.235 N/A
Dotted Hexadecimal 0xC0.0x00.0x02.0xEB Each octet is individually converted to hexadecimal form
Dotted Octal 0300.0000.0002.0353 Each octet is individually converted into octal
Hexadecimal
0xC00002EB Concatenation of the octets from the dotted hexadecimal
Decimal
3221226219 The 32-bit number expressed in decimal
Octal
030000001353 The 32-bit number expressed in octal
Some of these formats might work in web browsers. Additionally, in dotted format, each octet can be of any of the different bases. For example, 192.0x00.0002.235 is a valid (though unconventional) equivalent to the above addresses.
ALLOCATION
Originally, an IP address was divided into two parts, the network identifier represented in the most significant (highest order) octet of the address and the host identifier using the rest of the address. The latter was therefore also called the rest field. This enabled the creation of a maximum of 256 networks. Quickly this was found to be inadequate.To overcome this limit, the high order octet of the addresses was redefined to create a set of classes of networks, in a system which later became known as classful networking. The system defined five classes, Class A, B, C, D, and E. The Classes A, B, and C had different bit lengths for the new network identification. The rest of an address was used as previously to identify a host within a network, which meant that each network class had a different capacity to address hosts. Class D was allocated for multicast addressing and Class E was reserved for future applications.Starting around 1985, methods were devised to allow IP networks to be subdivided. The concept of the variable-length subnet mask (VLSM) was introduced which allowed flexible subdivision into varying network sizes.Around 1993, this system of classes was officially replaced with Classless Inter-Domain Routing (CIDR), and the class-based scheme was dubbed classful, by contrast.CIDR was designed to permit repartitioning of any address space so that smaller or larger blocks of addresses could be allocated to users. The hierarchical structure created by CIDR is managed by the Internet Assigned Numbers Authority (IANA) and the regional Internet registries (RIRs). Each RIR maintains a publicly-searchable WHOIS database that provides information about IP address assignments.
PRIVATE NETWORKS
Of the approximately four billion addresses allowed in IPv4, three ranges of address are reserved for use in private networks. These ranges are not routable outside of private networks and private machines cannot directly communicate with public networks.Following are the three ranges reserved for private networks
Name Address range Number of addresses Classful description Largest CIDR block
24-bit block 10.0.0.0 10.255.255.255 16777216 Single Class A 10.0.0.0/8
20-bit block 172.16.0.0 172.31.255.255 1048576 Contiguous range of 16 Class B blocks 172.16.0.0/12
16-bit block 192.168.0.0 192.168.255.255 65536 Contiguous range of 256 Class C 192.168.0.0/16
VIRTUAL PRIVATE NETWORKS
Packets with a private destination address are ignored by all public routers. Therefore, it is not possible to communicate directly between two private networks (e.g., two branch offices) via the public Internet. This requires the use of IP tunnels or a virtual private network (VPN).VPNs establish tunneling connections across the public network such that the endpoints of the tunnel function as routers for packets from the private network. In this routing function the host encapsulates packets in a protocol layer with packet headers acceptable in the public network so that they may be delivered to the opposing tunnel end point where the additional protocol layer is removed and the packet is delivered locally to its intended destination.Optionally, encapsulated packets may be encrypted to secure the data while it travels over the public network.
LINK-LOCAL ADDRESSING
RFC 5735 defines an address block, 169.254.0.0/16, for the special use in link-local addressing. These addresses are only valid on the link, such as a local network segment or point-to-point connection, that a host is connected to. These addresses are not routable and like private addresses cannot be the source or destination of packets traversing the Internet. Link-local addresses are primarily used for address autoconfiguration (Zeroconf) when a host cannot obtain an IP address from a DHCP server or other internal configuration methods.When the address block was reserved, no standards existed for mechanisms of address autoconfiguration. Filling the void, Microsoft created an implementation called Automatic Private IP Addressing (APIPA). Due to Microsoft's market power, APIPA has been deployed on millions of machines and has, thus, become a de facto standard in the industry. Many years later, the IETF defined a formal standard for this functionality, RFC 3927, entitled Dynamic Configuration of IPv4 Link-Local Addresses.
LOCALHOST
The address range 127.0.0.0 127.255.255.255 (127.0.0.0/8 in CIDR notation) is reserved for localhost communication. Addresses within this range should never appear outside a host computer and packets sent to this address are returned as incoming packets on the same virtual network device (known as loopback).
ADDRESS RESOLUTION
Hosts on the Internet are usually known not by IP addresses, but by names (e.g., en.wikipedia.org, whitehouse.gov, freebsd.org, berkeley.edu). The routing of IP packets across the Internet is not directed by such names, but by the numeric IP addresses assigned to such domain names. This requires translating (or resolving) domain names to addresses.The Domain Name System (DNS) provides such a system for converting names to addresses and addresses to names. Much like CIDR addressing, the DNS naming is also hierarchical and allows for subdelegation of name spaces to other DNS servers.The domain name system is often described in analogy to the telephone system directory information systems in which subscriber names are translated to telephone numbers.
ADDRESS SPACE EXHAUSTION
Since the 1980s it has been apparent that the number of available IPv4 addresses is being exhausted at a rate that was not initially anticipated in the design of the network.This was the driving factor for the introduction of classful networks, for the creation of CIDR addressing, and finally for the redesign of the Internet Protocol, based on a larger address format (IPv6).
Today, there are several driving forces for the acceleration of IPv4 address exhaustion:
Mobile devices laptop computers, PDAs, mobile phones
Always-on devices ADSL modems, cable modems
Rapidly growing number of Internet users
The accepted and standardized solution is the migration to IPv6. The address size jumps dramatically from 32 bits to 128 bits, providing a vastly increased address space that allows improved route aggregation across the Internet and offers large subnet allocations of a minimum of 264 host addresses to end-users. Migration to IPv6 is in progress but is expected to take considerable time.
Methods to mitigate the IPv4 address exhaustion are:
Network address translation (NAT)
Use of private networks
Dynamic Host Configuration Protocol (DHCP)
Name-based virtual hosting
Tighter control by Regional Internet Registries on the allocation of addresses to Local Internet Registries
Network renumbering to reclaim large blocks of address space allocated in the early days of the Internet
SUBNETTING
Three-level hierarchyis there, network, subnet, and host.The extended-network-prefix is composed of the classful network-prefix and the subnet-number.The extended-network-prefix has traditionally been identified by the subnet mask.
Network prefix Subnet-number Host-number
NETWORK ADDRESS TRANSLATION
The rapid pace of allocation of the IPv4 addresses and the resulting shortage of address space since the early 1990s led to several methods of more efficient use. One method was the introduction of network address translation (NAT). NAT devices masquerade an entire, private network 'behind' a single public IP address, permitting the use of private addresses within the private network. Most mass-market consumer Internet access providers rely on this technique.
PACKET STRUCTURE
An IP packet consists of a header section and a data section.The IPv4 packet header consists of 13 fields, of which 12 are required. The 13th field is optional (red background in table) and aptly named: options. The fields in the header are packed with the most significant byte first (big endian), and for the diagram and discussion, the most significant bits are considered to come first (MSB 0 bit numbering). The most significant bit is numbered 0, so the version field is actually found in the four most significant bits of the first byte, for example.
bit offset 0 3 4 7 8 13 14-15 16 18 19 31
0 Version Header Length Differentiated Services Code Point
Explicit Congestion Notification
Total Length
32 Identification Flags Fragment Offset
64 Time to Live
Protocol Header Checksum
96 Source IP Address
128 Destination IP Address
160 Options ( if Header Length > 5 )
160 or +192 Data
FRAGMENTATION AND REASSEMBLY
The Internet Protocol is the facility in the Internet architecture that enables different networks to exchange traffic and route traffic across one another. The design accommodates networks of diverse physical nature; it is independent of the underlying transmission technology used in the Link Layer. Link Layer networks of different hardware design usually vary not only in transmission speed, but also in the structure and size of valid framing methods, characterized by the maximum transmission unit (MTU) parameter. To fulfill the role of IP to traverse networks, it was necessary to implement a mechanism to automatically adjust the size of transmission units to adapt to the underlying technology. This introduced the need for fragmentation of IP datagrams. In IPv4, this function was placed at the Internet Layer, and is performed in IPv4 routers, which thus only require this layer as highest one implemented in their design.In contrast, the next generation of the Internet Protocol, namely IPv6, does not require routers to perform fragmentation; instead, hosts must determine the path maximum transmission unit in advance of transmission and send conforming datagrams.
FRAGMENTATION
When a device receives an IP packet it examines the destination address and determines the outgoing interface to use. This interface has an associated MTU that dictates the maximum data size for its payload. If the MTU is smaller than the data size then the device must fragment the data.
The device then segments the data into segments where each segment is less-than-or-equal-to the MTU less the IP header size (20 bytes minimum; 60 bytes maximum). Each segment is then put into its own IP packet with the following changes:
The total length field is adjusted to the segment size
The more fragments (MF) flag is set for all segments except the last one, which is set to 0
The fragment offset field is set accordingly based on the offset of the segment in the original data payload. This is measured in units of eight-byte blocks.
The header checksum field is recomputed.
For example, for an IP header of length 20 bytes and an Ethernet MTU of 1,500 bytes the fragment offsets would be: 0, (1480/8) = 185, (2960/8) = 370, (4440/8) = 555, (5920/8) = 740, etc.
By some chance if a packet changes page link layer protocols or the MTU reduces then these fragments would be fragmented again.For example, if a 4,500-byte data payload is inserted into an IP packet with no options (thus total length is 4,520 bytes) and is transmitted over a page link with an MTU of 2,500 bytes then it will be broken up into two fragments:
IPV4 ADDRESS ALLOCATION
NAT ADDRESS TRANSLATION
IPV6:
Internet Protocol Version 6 (IPv6) is a version of the Internet Protocol that is designed to succeed Internet Protocol version 4 (IPv4), the first publicly used Internet Protocol, which is still in dominant use currently. IPv6 is an Internet Layer protocol for packet-switched internetworks. The main driving force for the redesign of Internet Protocol was the foreseeable IPv4 address exhaustion. IPv6 is specified by the Internet Engineering Task Force (IETF) and described in Internet standard document RFC 2460, which was published in December 1998.
IPv6 has a vastly larger address space than IPv4. This results from the use of a 128-bit address, whereas IPv4 uses only 32 bits. The new address space thus supports 2128 (about 3.4 1038) addresses. This expansion provides flexibility in allocating addresses and routing traffic and eliminates the primary need for network address translation (NAT), which gained widespread deployment as an effort to alleviate IPv4 address exhaustion
Pv6 also implements new features that simplify aspects of address assignment (stateless address autoconfiguration) and network renumbering (prefix and router announcements) when changing Internet connectivity providers. The IPv6 subnet size has been standardized by fixing the size of the host identifier portion of an address to 64 bits to facilitate an automatic mechanism for forming the host identifier from Link Layer media addressing information (MAC address).
LARGER ADDRESS SPACE
The most important feature of IPv6 is a much larger address space than that of IPv4: addresses in IPv6 are 128 bits long, compared to 32-bit addresses in IPv4.The very large IPv6 address space supports a total of 2128 (about 3.4 1038) addresses or approximately 5 1028 (roughly 295) addresses for each of the roughly 6.8 billion (6.8 109) people alive in 2010. In another perspective, this is the same number of IP addresses per person as the number of atoms in a metric ton of carbon.While these numbers are impressive, it was not the intent of the designers of the IPv6 address space to assure geographical saturation with usable addresses. Rather, the longer addresses allow a better, systematic, hierarchical allocation of addresses and efficient route aggregation. With IPv4, complex Classless Inter-Domain Routing (CIDR) techniques were developed to make the best use of the small address space. Renumbering an existing network for a new connectivity provider with different routing prefixes is a major effort with IPv4.[With IPv6, however, changing the prefix announced by a few routers can in principle renumber an entire network since the host identifiers (the least-significant 64 bits of an address) can be independently self-configured by a host.The size of a subnet in IPv6 is always 264 addresses (64-bit subnet mask), the square of the size of the entire IPv4 address space. Thus, actual address space utilization rates will likely be small in IPv6, but network management and routing will be more efficient because of the inherent design decisions of large subnet space and hierarchical route aggregation.
DIFFERENCES BETWEEN IPV4 AND IPV6
IPv6 and IPv4 are both network layer protocols and play the same role in network architecture. IPv6 is designed based on I h 4 , and IPv6 adopts many new concepts that don t exist in IPv4. This section will narrate the differences between IpV6 and IPv4 from the point of testing. IPv6 eliminates or makes optional some of the IPv4 header fields to reduce the packet-bandling overhead, which provides some, compensation for the larger addresses. Even with the addresses, which are four times as long, the IPv6 header is only 40 octets in length (Fig 2), compared with 20 octets for 1Pv4 (Fig 3). Less header fields can expedite processing rate of router. IPv6 options
are placed in separate headers, located after IPv6 basic header, such that processing at every intermediate stop between source and destination may not be required. IPv6 defines many extension headers, such as fragment header, hop by hop option header, destination option header, routing header, routing header type 0, ICMPv6 (Intemet Control Message Protocol version 6) header, authentication header, encrypted security payload header, mobile header. IPv6 basic header does not contain any optional element. This does not mean that we cannot express options for special-case packets. The capabilities that the variable-sized option field offered in IPv4 are now deployed by a chain of extension headers that follow
Ver TC Flow Label
Payload Length Next header Hip limit
Source address
Destination address
IPv6 basic header.
Each IPv6 packet is composed of basic header and one or more extension headers and payload data, which makes IPv6 packets are provided with structural features (Fig 4). Each extension header has fixed length, accomplishes particular capability and is identified by next header field of the preceding header. However, Each 1Pv4 packet is composed of basic header and options and payload data (Fig 5). Option in IPv4 packet has variable length IPv4 packets have only one kind of structure, which is fixed length basic header + variable length data . IPv6 packets have countless kinds of structure, which are fixed length basic header + fixed lenglh extension header 1 + _.. ._. + fixed length extension header n + variable length data . In IPv6 packet format, each extension header may be one of ten kinds of possibility and the number of extension headers is variable, therefore the number of 1Pv6 packet structure is enormous. Besides the packet format, IPSec is another difference between IPv6 and IPv4 that influences test implementation. IPsec provides security services at the IP layer. IPsec can be used to protect one or more paths between a pair of hosts, between a pair of security gateways, or between a security gateway and a host. IPSec can be used in transport mode and tunnel mode. Transport mode provides protection primarily for upper layer protocols, and tunnel mode is applied to tunneled IP packets. IPSec is optional in IPv4, while mandatory in IPv6. IPv6 defines two extension headers, authentication header (AH) and encapsulating security payload header (ESP), to support IPSec. AH provides connectionless integrity, data origin authentication and anti-replay service. ESP provides confidentiality and all the service that AH can provide. Encryption algorithms (such as aescbc, des-cbc and 3des-cbc) and authentication algorithms (such as hmac-shal-96 and hmac-md5-96) should be implemented. These algorithms may be used to encrypt an packet in tunnel packet or to calcultate hash value from an packet. Computational procedure is very complicated and computational load is very huge
basic
header extension
header 1 extension
header 1 data(payltoad)
IPV6 packet
STATELESS ADDRESS AUTOCONFIGURATION
IPv6 hosts can configure themselves automatically when connected to a routed IPv6 network using Internet Control Message Protocol version 6 (ICMPv6) router discovery messages. When first connected to a network, a host sends a link-local router solicitation multicast request for its configuration parameters; if configured suitably, routers respond to such a request with a router advertisement packet that contains network-layer configuration parameters. If IPv6 stateless address autoconfiguration is unsuitable for an application, a network may use stateful configuration with the Dynamic Host Configuration Protocol version 6 (DHCPv6) or hosts may be configured statically. Routers present a special case of requirements for address configuration, as they often are sources for autoconfiguration information, such as router and prefix advertisements. Stateless configuration for routers can be achieved with a special router renumbering protocol.
ADDRESSING
The increased length of network addresses emphasizes a most important change when moving from IPv4 to IPv6. IPv6 addresses are 128 bits long, whereas IPv4 addresses are 32 bits; where the IPv4 address space contains roughly 4.3 109 (4.3 billion) addresses, IPv6 has enough room for 3.4 1038 (340 trillion trillion trillion) unique addresses. IPv6 addresses are normally written with hexadecimal digits and colon separators like 2001:db8:85a3::8a2e:370:7334, as opposed to the dot-decimal notation of the 32 bit IPv4 addresses. IPv6 addresses are typically composed of two logical parts: a 64-bit (sub-)network prefix, and a 64-bit host part. IPv6 addresses are classified into three types: unicast addresses which uniquely identify network interfaces, anycast addresses which identify a group of interfaces mostly at different locations for which traffic flows to the nearest one, and multicast addresses which are used to deliver one packet to many interfaces. Broadcast addresses are not used in IPv6. Each IPv6 address also has a 'scope', which specifies in which part of the network it is valid and unique. Some addresses have node scope or page link scope; most addresses have global scope (i.e. they are unique globally).Some IPv6 addresses are used for special purposes, like the loopback address. Also, some address ranges are considered special, like link-local addresses (for use in the local network only) and solicited-node multicast addresses (used in the Neighbor Discovery Protocol).
IPV4-MAPPED IPV6 ADDRESSES
Hybrid dual-stack IPv6/IPv4 implementations support a special class of addresses, the IPv4-mapped IPv6 addresses. This address type has its first 80 bits set to zero and the next 16 set to one, while its last 32 bits are filled with the IPv4 address. These addresses are commonly represented in the standard IPv6 format, but having the last 32 bits written in the customary dot-decimal notation of IPv4; for example, ::ff:192.0.2.128 represents the IPv4 address 192.0.2.128.
0000. .0000 FF IPV4 ADDRESS
Because of the significant internal differences between IPv4 and IPv6, some of the lower level functionality available to programmers in the IPv6 stack do not work identically with IPv4 mapped addresses. Some common IPv6 stacks do not support the IPv4-mapped address feature, either because the IPv6 and IPv4 stacks are separate implementations (e.g., Microsoft Windows 2000, XP, and Server 2003), or because of security concerns (OpenBSD).On these operating systems, it is necessary to open a separate socket for each IP protocol that is to be supported. On some systems, e.g., the Linux kernel, NetBSD, and FreeBSD, this feature is controlled by the socket option IPV6_V6ONLY .
TUNNELING
In order to reach the IPv6 Internet, an isolated host or network must use the existing IPv4 infrastructure to carry IPv6 packets. This is done using a technique known as tunneling which consists of encapsulating IPv6 packets within IPv4, in effect using IPv4 as a page link layer for IPv6.
The direct encapsulation of IPv6 datagrams within IPv4 packets is indicated by IP protocol number 41. IPv6 can also be encapsulated within UDP packets e.g. in order to cross a router or NAT device that blocks protocol 41 traffic. Other encapsulation schemes, such as used in AYIYA or GRE, are also popular.
AUTOMATIC TUNNELING
Automatic tunneling refers to a technique where the routing infrastructure automatically determines the tunnel endpoints. For automatic tunneling, which uses protocol 41 encapsulation. Tunnel endpoints are determined by using a well-known IPv4 anycast address on the remote side, and embedding IPv4 address information within IPv6 addresses on the local side. 6to4 is widely deployed today.
Teredo is an automatic tunneling technique that uses UDP encapsulation and can allegedly cross multiple NAT boxes. IPv6, including 6to4 and Teredo tunneling, are enabled by default in Windows Vista.Most Unix systems only implement native support for 6to4, but Teredo can be provided by third-party software such as Miredo.
ISATAP treats the IPv4 network as a virtual IPv6 local link, with mappings from each IPv4 address to a link-local IPv6 address. Unlike 6to4 and Teredo, which are inter-site tunnelling mechanisms, ISATAP is an intra-site mechanism, meaning that it is designed to provide IPv6 connectivity between nodes within a single organisation.
CONFIGURED AND AUTOMATED TUNNELING (6IN4)
In configured tunneling, the tunnel endpoints are explicitly configured, either by an administrator manually or the operating system's configuration mechanisms, or by an automatic service known as a tunnel broker; this is also referred to as automated tunneling. Configured tunneling is usually more deterministic and easier to debug than automatic tunneling, and is therefore recommended for large, well-administered networks. Automated tunneling provides a compromise between the ease of use of automatic tunneling and the deterministic behaviour of configured tunneling.
Raw encapsulation of IPv6 packets using IPv4 protocol number 41 is recommended for configured tunneling; this is sometimes known as 6in4 tunneling. As with automatic tunneling, encapsulation within UDP may be used in order to cross NAT boxes and firewalls.
IPV6 Datagram Fragmentation
The maximum transfer unit is 230 bytes.Extension header is of size 30 bytes.
CONCLUSION
Even though consumers are most likely to suffer when their equipment has to be replaced they tend to look at networking devices like household appliances that only rarely need repairs and never have to be configured or updated. Commercial grade equipment is more likely to support IPv6, so it is the small consumer with his cost-effective disposable networking technology who will be most affected by the eventual change from IPv4 to IPv6.
Smart equipment that contains software needs explicit IPv6 support. Lower-level equipment like cables, network adapters, and switches may not be affected by the change. In general, layer-1 and layer-2 equipment won't require updates.
IPv6 compatibility is mainly a software/firmware issue like the year-2000. Unlike the year-2000 issue, there is little interest in ensuring compatibility of older equipment and software by manufacturers. The realization that IPv4 exhaustion is imminent is recent and manufacturers haven't shown much initiative in updating equipment. There is hope that a combined IPv4/IPv6 internet will streamline the transition. The internet community is divided on the issue of whether the transition should be a quick switch or a longer process. It has been suggested that all internet servers be prepared to serve IPv6-only clients by 2012. Universal access to IPv6-only servers will be even more of a challenge.
REFERENCES
YUJUN ZHANG, ZHONGCHENG LI, IPV6 CONFORMANCE TESTING: THEORY AND PRACTICE,2010 IEE PROCEEDINGS .
J. GNANA JAYANTHI AND S. ALBERT RABARA IPV6 ADDRESSING ARCHITECTURE IN IPV4 NETWORK , IEE PROCEEDINGS OF THE 2010 SECOND INTERNATIONAL CONFERENCE ON COMMUNICATION SOFTWARE AND NETWORKS.
RAJA KUMAR MURUGESAN AND SURESWARAN RAMADASS IMPROVING THE PERFORMANCE OF IPV6 PACKET TRANSMISSION OVER LAN , 2009 IEE SYMPOSIUM ON INDUSTRIAL ELECTRONICS AND APPLICATIONS (ISIEA 2009), OCTOBER 4-6, 2009, KUALA LUMPUR, MALAYSIA