IPv6

IPv6 stands for Internet Protocol version 6.

Basically it is newer version of IP address. Currently, IPv4 is being used. But it has some limitations. Like...

• Number of available addresses.
  
  Because of increasing number internet users and internet using applications,the number of addresses available is decreasing day by day.
  
  
  
  
• Security
  
  IPv4 was published in 1981 and current security problems weren't present at that time. So Providing security to IPv4 is very difficult.
• Complex address configuration.
  
  Because of increase in number of internet users and internet applications, the address configuration has become complex.
  
  
• Quality of Service(QoS). based
  
  Quality of Service (QoS) is available in IPv4 and it relies on the 8 bits of the IPv4 Type of Service (TOS) field and the identification of the payload. IPv4 Type of Service (TOS) field has limited functionality and payload identification (uses a TCP or UDP port) is not possible when the IPv4 packet payload is
  encrypted.
  
  
  

These limitations has been over come in IPv6. Key features of IPv6 are as under.

• Number of addresses available.
  
  
  
  IPv4 uses 32 bit address. That means it has 2³² = 4,294,967,296 available addresses.
  
  Whereas IPv6 uses 128 bit address. That means it has
  2¹²⁸ = 340,282,366,920,938,463,463,374,607,431,768,211,456
  available addresses.
Which is 79,228,162,514,264,337,593,543,950,336 times more than IPv4. That means approx ∼ 5 x 10²⁸ addresses per person on the planet.

• Example of IPv6 address.
  
  IPv4 address:198.10.0.0/16
  
  IPv6 address: 2001:db8:12::/40
  
  
  
• Types of addresses.
  
  
  
  Unicast : One to One (Global, Unique Local, Link local)
  
  Anycast : One to Nearest (Allocated from Unicast)
  
  Multicast : One to Many.
  
  
  
• IPv6 Header format is shown below.
  
  
  
  
  
  
• Decomposition of IPv6 address in to its binary form is shown below.
  
  
  
  
  

• 8 June 2011 was named as IPv6 day.