IPv6 Features Summary

In the previous article, we summarized the geological structure characteristics of the IPv6 protocol. I don't know if you still remember it. We will continue to add other advantages of this agreement today. First, we will consolidate the address configuration, and then describe its security and other aspects in detail.

(1) stateful and Stateless Address Configuration

To simplify host configuration, IPv6 supports both stateful Address Configuration (for example, Address Configuration when a DHCPv6 server is available) and Stateless Address Configuration (for example, in the absence of a DHCPv6 server ). In Stateless Address configuration, the host on the Link automatically configures the IPv6 address (called the local link address) suitable for this link, or the IP address suitable for IPv4 and IPv6 coexistence, or the IP address prefixed by the local router. Even if no vro is available, all hosts on the same link can automatically configure their local link addresses so that communication can be performed without manual configuration. The local link address can be automatically configured within one second, so the communication between nodes on the same link is almost done immediately. In contrast, an IPv4 host using DHCP takes an entire 1 minute: First discard the DHCP configuration, and then configure an IPv4 address.

(2) built-in security

IPv6 supports IPSec, which provides a standard-based solution for network security and improves interoperability between different IPv6 implementation solutions. IPSec consists of two different types of extension headers and a protocol for processing security settings. The Authentication Header (AH) provides data integrity, data verification, and replay protection for data packets of the entire IPv6 network protocol, except for fields that must be changed during transmission. The header and tail of the encapsulated Security packet (ESP) also provide data integrity, data verification, data confidentiality, and replay protection for the ESP encapsulated packets. In unicast communication, the protocol used to handle IPSec security settings is generally Internet Key Exchange Protocol (IKE ).

(3) better Qos support

As multimedia applications become increasingly widespread today, the provision of the Internet will be of great significance for multimedia support. Multimedia is generally characterized by high bandwidth requirements and long duration. To this end, the concept of introducing people simplifies multimedia processing over the Internet. A stream is a sequence of packets between a specific source and destination. The source requires the intermediate router to perform special processing on these packets. Generally, after a vro receives a message in the stream, it searches for the stream context stored in the vro Based on the stream identifier, and processes the packets in the stream in the same way, accelerating the packet processing speed. IPv4 supplements stream processing, such as using Resource Reservation Protocol (RSVP) to reserve resources for audio and video transmission over the Internet. However, IPv4 streaming processing is inherently flawed because there is no stream concept at the beginning of IPv4 definition. IPv4-defined streams include the source and destination IP addresses, Transmission Control Protocol (TCP), or User Datagram Protocol (UDP) port numbers. To determine whether a packet belongs to a stream, not only the IP address in the IP header, but also the port number in the UDP header in the TCP Header, which not only violates the network layering principle, but also increases the processing workload of the router. At the beginning of the design, the IPv6 Protocol considered the support of streaming. In the IP Header Format, there is a dedicated 20bit stream tag domain. When the host sends a message, if you need to put the message in the stream for transmission, you only need to fill in the corresponding stream number in the stream label, otherwise fill in the stream label as a general message processing. When a vro receives the first packet of a stream, the processing context is created based on the stream ID. Subsequent packets in the stream are processed according to the context. Because the communication flow is identified in the IPv6 protocol header, even if the packet payload has been encrypted using IPSec and ESP, Qos can still be supported.

(4) use the new protocol to process interactions between neighboring nodes

The Neighbor Discovery Protocol in IPv6 is a series of IPv6 protocol network control packet protocol (ICMPv6) packets used to manage the interaction between adjacent nodes (nodes on the same link. The adjacent Node Discovery protocol uses more effective multicast and unicast adjacent node discovery packets, replacing the Address Resolution Protocol (ARP) (broadcast-based) and ICMPv4 router discovery, and ICMPv4 redirection packets.

(5) scalability

IPv6 can be easily extended by adding a new extension protocol header after the IPv6 network protocol header. The options in the IPv4 header can support up to 40 bytes, while the length of the IPv6 extension header is limited only by the length of the IPv6 packet.