IPv6 is a next generation layer 3 protocols that transfers data securely through Internet.
Currently the IP protocol version4 is used. However it has some limitations.
- Maximum number of address available – 4.3 billion (approx.), but Class D and Class E are not used to assign to computers.
- There is no inbuilt security in ipv4.
Till now the first limitation of using PRIVATE address, CIDR and NAT/PAT has not been solved. As the network of India, China and some others countries are growing fast so this IPV4 address range is now about to end. Additionally NAT/PAT also creates some problem like end to end security or complex network design, so there is a need to move to another new network protocol and addressing scheme IPV4 -> IPV6.
A simple comparison between IPV4 and IPV6 is as below:
IPv6 address space:
IPV4: 232 =4,294,967,296 (4.3 billion approx.)
IPV6: 2128 =340,282,366,920,938,463,463,374,607,431,768,211,465
Thus one can get 79 trillion times more addresses than total number of IPV4 addresses
2128 =232 * 296 (79 trillion trillion)
2030:A1B2:25C9: AAAA: 1234: DBCA: 21B4:555C
IPV6 support abbreviations-
IPv6 address “2010:0000:0000:0000:0000:0000:0000:140B” can be shorten to-
But if there is any digit or number between continuous “0″ like
2010::130F:: 140B is incorrect , because more than one double colon (::) in one address cannot be used.
At least one should write one “0” for each quartet (4 hex digit).
IPv6 ADDRESS TYPES:
IPv6 Unicast address is of 3 types
Global Unicast: It works like original IPv4 Public address.
Link-Local Unicast: Every IPv6 host interface (and router interface) can create their own link-local address automatically. It can work only in local Subnet.
Unique-local Unicast: Works somewhat like private IPv4 addresses.
At first there were thought of having two distinct components.
- 64-bit field designated as the network portion.
- 64-bit field designated as the host portion
- Dual-stack techniques- Allows IPv4 and IPv6 to co-exist in the same devices and networks.
- Tunnelling techniques- Tunneling is an integration method in which an IPv6 packet is encapsulated within another protocol, like IPv4.
- Translation techniques- Allows IPv6-only devices to communicate with IPv4-only devices.
Problems with ipv6 Implementation
- Complex Addressing.
- Administrators and Network Engineers are not trained.
- Older devices do not support ipv6 properly.
- Tough to change whole internet addressing scheme all at once.
So there is a need to increase the use of IPv6 address parallel to IPv4. Then IPv4 will be dropped and IPv6 will take command of the whole Network.