Sunday 9 September 2012

Difference between IPv4 and IPv6


IPv6 world launch day is on 8 June 2011 , next event held on 6 June 2012.

Here I am listing main difference between the two protocols.


1) IPv4 : RFC 791
    IPv6 : RFC 2460


2) IPv4 : Address size : 32 bits
    IPv6 : Address size :  128 bits

3) IPv4 : unicast, multicast, broadcast
    IPv6 : unicast , multicast ( some changes ),  anycast
   
4) IPv4 routers : Does Fragmentation
    IPv6 routers : No fragmentation (Pv6 host should perform path mtu discovery or do end-to end fragmentation)

5) IPv4: default PATH MTU 68  
    IPv6 : default PATH MTU 1280

6)  Minimum datagram which host should accept : IPv4 : 576
                                                                            IPv6 : 1280

7) Payload limit : IPv4 : 65535 ((216−1)
                          IPv6 : 4294967295 (232−1) , known as Jumbograms

8) IPv4 : TTL ( Time to Live)
    IPv6 : Hop Limit ( same functionality only name change)

9) Header :

 a)        IPv4 : check sum present
            IPv6 : No check sum

b)         IPv4 : Includes "option"
            IPv6 :  Separate " extension header" not in IPv6 header

c)       IPv4 : IPsec optional
          IPv6 : IPsec compulsary

10) IPv4 : Address ( Manual/DHCP)
       IPv6 : Stateless auto configuration ( link local)

11) IPv4 : To resolve IP->MAC  -> ARP broadcast
      IPv6 : To resolve IP->MAC  -> Multicast solicitation messages ( neighbor discovery protocol)

12) IPv4 -> Broadcast to all hosts
      IPv6 -> Link local all nodes multicast group ( to send to all nodes)