The Advantages of IPv6

IPv6 was designed to overcome the limitations of IPv4. The main advantages that IPv6 has over its predecessor are as follows:

• Increased address space IPv6 provides sufficient addresses for every device that needs to have a unique public IPv6 address. In addition, the 64-bit host portion (interface ID) of an IPv6 address can be automatically generated from the network adapter hardware.
• Automatic Address Configuration Typically IPv4 is configured either manually or by using DHCP. Automatic configuration (autoconfiguration) through APIPA is available for isolated subnets that are not routed to other networks. IPv6 deals with the need for simpler and more automatic address configuration by supporting both stateful and stateless address configuration.
• Network level security Communication over the Internet requires encryption to protect data from being viewed or modified in transit. Internet Protocol Security (IPSec) provides this facility and IPv6 makes IPSec mandatory.
• Real-time data delivery Quality of Service (QoS) exists in IPv4, and bandwidth can be guaranteed for real-time traffic over a network, but not when an IPv4 packet's payload is encrypted. Payload identification is included in the Flow Label field of the IPv6 header, so payload encryption does not affect QoS operation.
• Routing table size On the IPv6 Internet, backbone routers have greatly reduced routing tables that use route aggregation, which permits a number of contiguous address blocks to be combined and summarized as a larger address block.
• Header size and extension headers IPv4 and IPv6 headers are not compatible, and a host or router must use both IPv4 and IPv6 implementations to recognize and process both header formats. Therefore, the IPv6 header was designed to be as small as was practical. Nonessential and optional fields are moved to extension headers placed after the IPv6 header.
• Removal of broadcast traffic IPv4 relies on ARP broadcasts to resolve the MAC addresses of the network adapters. The IPv6 Neighbor Discovery (ND) protocol uses a series of ICMPv6 messages. ND replaces ARP broadcasts, ICMPv4 Router Discovery, and ICMPv4 Redirect messages with efficient multicast and unicast ND messages.