Today in this post I am going to discuss about IPV6 (Internet Protocol Version 6).
The number of users on the internet are increasing every day and the services offered to these users are also increasing. So, IPV6 is the latest version of the Internet Protocol.
What is Internet Protocol Version 6 (IPV6):
The internet Protocol version 6 has been designed for the future needs of the internet. IPV6 carries out the data in the form of packets from source to destination through various networks. It can also support the large number of address space because it has 128 bit space. The most normal change in IPV6 compared to IPV4 is that the IP address is extended from 32 bits to 128 bits.
History of IPV6:
The usage of internet these days increased rapidly. In the year 1990’s IPv6 has came into the picture which is going to replace the widely used Internet Protocol IPV4. IPV6 is the Upgrade version of IPV4, because IPV4 has some limitations like
- Limited number of IP addresses
- No provision for encryption, decryption and authentication
- Inefficient provision for routing
So, to overcome the limitations of IPV4 Internet Engineering Task Force (IETF) introduced new generation of IP addressing called IPv6.
The IP addressing system which has been developed to replace IPv4(In other words IPv6 is the successor of IPV4). An IPV6 address is a 128-bit binary address displayed in a 32 hexadecimal digits. So, with this extended address space it can provide the high capability addresses to each and every node or device over the internet.
Here, in IPV6 colons separate entries in a series of 16-bit hexadecimal field arranged in eight blocks. It provides 360 undecillion IP addresses. For Example,
FDEC : BA98 : 7654 : 32I0 : ADBF : BBFF : 2922 : FFFF
Therefore, here each field is a 16-bit hexadecimal number separated by a colon. Now, we look on to the conversion with help of example.
Hence, the first three blocks are represented by the global prefix, the fourth block being represented by the subnet and the fifth to eighth blocks by Interface ID.
Let’s see the IPV6 conversion using the binary digits where as in IPV6 address format each hexadecimal character represents 4 bits so, we need to convert 4 bits at a time to get one hexadecimal value by using bit and alphabet chart.
Below is the conversion of binary digit into hexadecimal format
This is how we convert four bit binary digits into hexadecimal format by using bit chart and alphabet or character chart.
Types of IPV6 addresses:
This IPV6 address format categorised into three types
Unicast address (one to one) : This address is assigned to only single interface. Therefore, uni cast address is classified into three classes, they are
- Global unicast
- Link local
- Unique local
Anycast address (one to closest node) : An address for multiple interfaces on different nodes
Multicast address (one to many) : Multicast behaves in same way in IPV4 and IPv6. It works as a group interfaces on different nodes.
IPV6 Datagram format:
IPV6 datagram or packet format consists of two parts 1) Base or fixed header 2) Extension or optional header. The base header occupies 40 bytes and important information for the router is stored in this base header. Meanwhile, the Extension header occupies up to 65,535 bytes of information that is optional.
Base header consists of
- Traffic class
- Flow label
- Payload length
- Next header
- Hop limit
- Source IP address
- Destination IP address
Now, we see the brief explanation of each and every field
Base or Fixed headers:
Version is a 4 bit field which defines the version of the Internet protocol i.e; 6 in this field.
2. Traffic class:
It defines the priority or class of the packet concerning traffic congestion which is similar to the service type in IPV4 hence, it is a 4 bit field.
3. Flow label:
It specially manages the particular flow of the data to maintain the sequential flow of packets for communication. Hence it is a 24 bit field.
4. Payload length:
It defines the total length of the IP datagram including the base header and it is a 16 bit field.
5. Next header:
It is a 8 bit field which specifies the header that follows the base header in the datagram. The next header is one of the optional headers which IP uses or it can be used by upper layer protocols like UDP and TCP.
6. Hop limit:
This 8 bit Hop limit field serves the same purpose as time to live field in IPV4 which determines the duration of data on the internet.
7. Source IP address:
It is a 16 byte Ip address which identifies the source of the datagram.
8. Destination IP address:
This is also 16 byte IP address which identifies the final destination of the IP address.
Extension or Optional headers:
In payload all information is placed between the Fixed Header and the top layer header in the form of an Extension Header. In Extension header optional information will help the routers to understand how to manage the packet low. Therefore, extension header consists of
- Fragmentation header
- Routing header
- Hop-by-Hop options
- Encapsulating security payload header
- Destination option header
Thus, we have seen many changes in IPV6 when compared to IPV4. So, now we check with deleted and revised fields
Revised fields in IPV6:
- In the place of Time to live changed to Hop limit
- Protocol to Next header
- Type of service to Traffic class
- Address size increased
- Flow label added
Deleted fields in IPV6:
- Fragmentation fields eliminated
- Header checksum eliminated
- Header length field eliminated
- Options moved from header into payload
- Identification field eliminated
Benefits of IPV6:
- IPV6 has large address space
- It has security and mobility
- It has extensions and headers
- Improves the performance
- It does not require any manual configuration
- Transition richness
Limitations of IPV6:
- It becomes harder to remember the IP addresses
- IPV6 has more internet traffic
- Some local networking changes
- Up-gradation cost for smaller business
By the above information you got brief idea about Internet Protocol Version 6 and there features. If you have any queries you can mention in the comment section below.