IPv4 to IPv6 Transition part-3

IPv6 transition

The differences between IPv4 and IPv6 can be overcome by creating a method of Hosts - dual stack and Networks - Tunneling on network devices, such as routers and servers. So each router receives a packet, the router will sort out the packet
to determine the protocol used, then the router will forward to the layer above it. In this way can also guarantee implementation of communication between users of IPv4 and IPv6 users.  Look at the picture below.

 

Sample of Infrastructure in IPv6

 

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IPv4 to IPv6 Transition - part 2

Addressing in IPv6

A. Unicast Address (one-to-one) 

Used to communicate one on one, by pointing to one host. On Unicast address consists of:  

1. Global, addresses that are used for example to address provider or address geographical.  
2. Link Local Address is the address used within one link only. Which referred to here is the link local network connected to each other on one level. This address is created automatically by the host that has not received global address, consisting of 10 n-bit prefix that begins with "fe80" and the fields along the 118-n bits indicating the number of hosts. Link Local Address used in the provision of an IP address automatically.
3. Site-local, which is equivalent to a private address address, which is used is limited in the site only. This address can be given freely, provided unique within the site , but can not send packet with the destination address in outside of the site. 
4. Compatible

B. Multicast (One-to-many)

Multicast is used for one-on-many communication with the host of the group pointed. This in IPv4 multicast address is defined as a class D, selected based on range goals.

C. Anycast

It's refers to the host of the group, but the packets are sent only on one host only. In this type of address, an address given at multiple hosts, to define a collection of nodes. If any packets sent to this address, the router will send packets to the nearest host that has the same Anycast address. In other words, the owner handed the package to the destination router of the most "suitable" for the delivery of the package. Use this example to multiple Anycast servers that provide services such as DNS (Domain Name Server). By providing Anycast Address same address on those servers, if there are packets sent by a client to this address, the router will choose the nearest server and sends the packet to the server. Thus, the load on the server can be distributed evenly. For anycast is not provided specific rooms. If against multiple hosts are given a same address, the address is regarded as Anycast Address.

How IPv6 Address is written ?

IPv6 Address is using model x: x: x: x: x: x: x: x where 'x' in the form of 16-bit hexadecimal value portion of the address, because there are 8 pieces of 'x' is the sum total there are 16 * 8 = 128 bits. An example is

          FEDC: BA98: 7654: 3210: FEDC: BA98: 7654: 3210

If the format of IPv6 addressing group contains a collection of 16-bit addresses, ie
'x', which is 0 then it can be represented as'::'. Examples are:

                      FEDC: 0: 0: 0: 0: 0: 7654: 3210

It can be represented as FEDC:: 7654: 3210 And 0:0:0:0:0:0:0:1 can be represented as:: 1
Model x: x: x: x: x: x: dddd where 'dddd' is the IPv4 address of a kind
167.205.25.6 is used for automatic tunneling. Examples are:

                       0:0:0:0:0:0:167.205.25.6 or:: 167.205.25.6
                    0:0:0:0:0: ffff: 167.205.25.7 or: ffff: 167.205.25.7

So if now access the address on the internet for example 167.205.25.6 in time format will be replaced by a kind ::ba67: 080:18. As with IPv4, IPv6 uses bitmask for the purposes subnetting is represented as prefix-length representation on CIDR techniques used in IPv4, such as: 3ffe: 10:0:0:0: fe56: 0:0 / 60

showed that 60 bits are network side bit early. If the IPv4 IP recognize the division of classes into class A, B, and C then the IPv6 was conducted based on class divisions fomat prefix (FP) is the initial bit address format. For example:

                                   3ffe: 10:0:0:0: fe56: 0:0 / 60

then if the note 4 bits beginning of hexa '3 ' prefix obtained for 4-bit format is the beginning of 0011 (ie the value '3' hex in binary).

IPv6 class

There are several important classes of IPv6 are:

1. Aggregatable Global Unicast Addresses: it includes the addressIPv6 with 001 bit early. 
2. Link-Local Unicast Addresses: it includes the IPv6 address with a bit early 1111 1110 10.
3. Site-Local Unicast Addresses: it includes the IPv6 address with a bit early 1111 1110 11.
4. Multicast Addresses: it includes is a bit IPv6 address beginning of 1111 1111. In the IPv4 protocol known addresses 127.0.0.1 is a special kind refer to localhost, this address is represented as 0:0:0:0:0:0:0:1 or :: 1 in IPv6 protocol. In addition to the known IPv6 addresses and other special

0:0:0:0:0:0:0:0 is known as the unspecified address must not be is given as recognition to an interface.

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IPv4 to IP6 Transition - part 1

According to the issues being discussed so much that the IPv4 which is the foundation of the Internet has nearly approaching the ultimate limit of his ability.It will be a transition mechanism from IPv4 to IPv6 model which is a new protocol has been designed to be able to replace the function of IPv4. The main motivation for the change is due to the limitations of IPv4 addresses that long only 32 bit only and are not able to support the need for secure communications, flexible routing and traffic regulation data.

IP version 6 (IPv6) is a new version of Internet protocol that is designed as the successor of Internet protocol version 4 (IPv4) which is defined in RFC 791. IPv6 address that has a huge capacity (128 bits), supporting the preparation of a structured addressing, which allows the Internet continues to evolve and provide new routing capabilities which not found in IPv4. The anycast address of IPv6  has a type that can be used to efficiently route selection. IPv6 is also supplemented by mechanisms address utilization locally which allows the realization of the installation is Plug & Play, as well as provide a platform for new ways of using the Internet, such as support to the flow of data in real-time, the selection of providers, mobility of hosts, end-to-end security, or automatic configuration.


The Advantages of IPv6

1.  Automation of the various settings

Automation of the various settings / Stateless-less auto-configuration (plug & play) on the IPv4 Address to host essentially static. Usually administered sequentially on the host. It is now can be done automatically by using DHCP (Dynamic Host Configuration Protocol), but it is on IPv4 only an additional function, otherwise the function for setting up IPv6 automatically provided by default. In this automatic setting, there are 2 ways depending on the use of address, namely stateless and statefull automatic settings.

• Automatic Statefull Settings
  Automatic Statefull Settings is the way the management of strictly in terms of range of IP addresses provided on the host by providing a server for state management IP address, which means it is almost similar to the way DHCP in IPv4. At the time of doing the settings automatically, the information required between routers, servers and hosts are ICMP (Internet Control Message Protocol) which has been expanded. In the ICMP in IPv6, including the IGMP (Internet Group Management Protocol) used on multicast in IPv4.

• Stateless Auto setting

Stateless Auto setting  does not need to provide a server for managing and sharing an IP address, just setting up the router is just where the host has been connected in a network of routers that exist on the network prefix of the address obtained from the network. Then the hosts increase the bit pattern obtained from the information that is unique to the host, then create a 128-bit IP address and making it an IP address from that host. On information unique to this host, used among other MAC addresses of network interfaces. In this stateless automatic setting behind the ease of management, on an Ethernet or FDDI because of the need to give at least 48 bits (by MAC address) against one network, has the disadvantage of a bad address utilization efficiency.

2. Address  Capacity Expansion

IPv6 increases the size and number of addresses that can be supported by IPv4 from 32 bit to 128bit. Increasing the capacity of these addresses are used to address capacity can be allocated and administered in the nodes and simplify configuration on the node address so it can be done automatically. Improved scalability of multicast routing is also done in by increasing the scope and number of the multicast address. IPv6 addresses in addition to increasing the amount of capacity that can be allocated on the node is also introducing a new address type or types, in example anycast address. Anycast address type is defined and used to send packets to one of a collection of nodes.

3. Header Format Simplification

Some of the fields in IPv4 header has been removed or to be created as a header option. It's used to reduce the cost of processing the things common to the handling of IPv6 packets and limit the cost of bandwidth in IPv6 header. Thus, the IPv6 packet header processing can be done efficiently.

4. Options and Extension Headers

It's changes that occur in IP headers that is the presence of encoding header Options (option) on the IP entered to be more efficient in forwarding packets (packet forwarding), so as not to be too strict in limiting the length of the header options contained in the IPv6 packet and highly flexible / possible to introduce a new option header in the future.

5. Flow Labeling Capability Package

Capabilities or new features added to IPv6 is that it allows package labeling or classifying packets that require special handling, such as the quality of a certain quality of service (QoS) or real-time.

6. Authentication and Privacy Capabilities

Additional capabilities to support authentication, data integrity and critical data are also specified in the IPv6 address. The biggest change in IPv6 is the expansion of the IP address of 32 bits in IPv4 to 128 bits.
The 128 bit address space which is continuous by eliminating the concept of class. It also made ​​changes to the way of writing the IP address. If the IPv4 32 bits divided into 8 bits each of which separated it with "." and written as a decimal, then on IPv6, 128 bits are separated into each of 16 bits each section separated by ":" and written with a hexadecimal. In addition it also introduced tiered structure to manage the routing becomes easy. In CIDR (Classless interdomain routing) routing table is minimized by combining into one routing information of an organization.

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