IPv4 vs IPv6

    . IPv4 and IPv6 are two generations of Internet Protocols.
    . IPv4 was the first version deployed in year 1983.
    . It contains 32-bit address which results in 4.3 billion addresses.
    . But 4.3 billion address are not efficient to cover all the devices using internet.
    . To overcome this problem, Internet Engineering Task Force developed new version of Internet Protocol namely IPv6 in 1990.
    . It is 128-bit address which results in some trillions of unique address which are far enough to future use.
    . IPv4 coexits with IPv6 untill the complete address spaces of IPv4 gets allocated.

   Advantages of IPv6 over IPv4:

       . Auto configuration.
       . Buit-in authentication and security.
       Infinite Address Spaces.
       . No need of NAT(Network Address Translator).
       . No need of DHCP servers to configure IP Addresses.
       . More compatible with mobile networks.
       Allows bigger payloads.

    Differences between IPv4 and IPv6:

Address Length32 bits128 bits
Number of Addresses it supports4.3 billionInfinite
Address RepresentationDecimal formatHexadecimal
Header20 bytes, 13 fields40 bytes, 8 fields
ISP ConnectivityConnects to IPv4 or both IPv4 and IPv6Many ISP don't have connectivity
SecurityLack of securityHas built in strong security
Domain Name SystemEx:A record provides domain name to IPv4Ex:AAAA record provides same domain name to IPv6
FragmentationDone by sender and forwarding routersDone by sender only
ConfigurationManual or DHCP server configures addressesAuto configuration is available
Usage99% of networks use IPv41% shifted using IPv6