Differences Between IPv4 and IPv6

Differences Between IPv4 and IPv6

1. Elimination of NAT to extend address spaces. IPv6 increases the IPv4 address size from 32 bits (about 4 billion) to 128 bits

2. Network layer security built-in (IPsec). Security, always a challenge in IPv4, is an integral part of IPv6.

3. Stateless address autoconfiguration for easier network administration. IPv6 handles this in an automated fashion.

4. IPv6 packets have their own frame Ethertype value, 0x86dd, making it easy for receivers that must handle both IPv4 and IPv6 to distinguish the frame content on the same interface.

5. IPv6 uses a more integrated address space for multicast, at FF00::/8.

6. IPv6 does away with broadcast and uses multicast groups for everything.

7. IPv4 contains broadcast but IPv6 does not contain broadcast but uses multicast.

8. Pv4 uses globally unique public addresses for normal traffic and special “private” addresses. Instead, IPv6 uses globally unique unicast addresses and local addresses (FD00::/8).

9. So IPv6 does away with the rigid class concept (it was already obsolete in IPv4) and uses subnetting (more on that later) to adjust network sizes with a given address space assignment.

10. IPv6 uses 128-bit addresses, the pool of possible addresses is 340 undecillion (3.4×1038). IPv4’s 32-bit addresses allow for only 4.3 billion addresses.

11. Improved header structure with less processing overhead. IPv6 eliminates these fields (options are handled differently).

    • Version: A four-bit field for the IP version number (0x06).
    • Traffic Class: An 8-bit field that identifies the major class of the packet content(for example, voice or video packets).
    • Flow Label: A 20-bit field used to label packets belonging to the same flow(those with the same values in several TCP/IP header parameters).

12. Quality of service (QoS) built-in. IPv4 has no way to distinguish delay-sensitive packets from bulk data transfers, requiring extensive workarounds, but IPv6 does.

13. More efficient routing. IPv6 routers no longer have to fragment packets, anoverhead-intensive