Understanding and using IPV6

1. What is IPv6

IPV6 refers to the Internet Protocol (IP) version 6th. At present, we mainly use Internet Protocol Fourth edition, namely IPv4. With the global Internet highly developed today, IPV4 address resources have dried up and the internet is undergoing a transition from IPV4 network to IPV6 network. The IPV4 address is similar to the A.B.C.D format, with a total of 32 bits. Divided into four segments, expressed in 10 notation, and the IPV6 address is similar to the x:x:x:x:x:x:x:x format, it is 128-bit, with: divided into 8 segments, denoted by 16 binary. RFC2373 defines the IPV6 address in detail, by definition, a complete representation of the IPV6 address: xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx.

Header Structure
The structure of the new IPV6 header is much simpler than the IPv4, and the IPV6 header removes many of the infrequently used fields in the IPV4 header, into the optional and header extensions, and the options in IPV6 are more strictly defined. There are 10 fixed-length domains, 2 address spaces, and several options in IPv4, with only 6 domains and 2 address spaces in the IPV6.
Although the IPV6 header accounts for 40 bytes and is 1.6 times times the 24-byte IPv4 header, it does not need to consume excessive memory capacity because its length is fixed (the IPV4 header is variable).
Header length in IPv4, service type (type of Service,tos), identifier (identification), flag (flag), segment offset (fragment Offset) and header checksum (header checksum) of these 6 domains are deleted. The total length of the message, the Protocol type (protocol type), and the time to Live,ttl 3 domain names or parts of the function have been changed, and the options feature has been completely changed, adding 2 new domains, priority and flow labels. 2. IPv4 Address and IPv6 the difference between addresses

IPv4 Address	IPv6 Address
Multicast address (224.0.0.0/4)	IPV6 multicast address (FF00::/8)
Broadcast Address	None, only anycast (anycast) address
The address specified is 0.0.0.0	Address not specified is::
The Loop address is 127.0.0.1	Loop Address:: 1
Public IP Address	Global unicast addresses can be aggregated
Private addresses (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16)	Local Site address (FEC0::/48)
Microsoft Automatic Private IP addressing automatic configuration address (169.254.0.0/16)	Local link address (FE80::/64)
Expression: Dot interval decimal	Expression: Colon interval 16-in-mode
Subnet mask representation: In dotted-dot decimal notation or prefix length notation (CIDR)	Subnet mask representation: Use only prefix length notation (CIDR)

3. There are some notable advantages to Ipv4,ipv6 compared to the following:

(1) The address capacity expands greatly, from the original 32 bits to 128 bits, completely solves the problem that the IPV4 address is insufficient, supports the hierarchical address structure, thus is easier to address, and extends the support multicast and anycast address, which makes the packet can be sent to any one or a set of nodes;
(2) Large capacity address space can truly realize stateless address automatic configuration, so that the IPV6 terminal can be quickly connected to the network, without manual configuration, to achieve a real plug and play;
(3) The header format is greatly simplified, which effectively reduces the processing overhead of the router or switch to the header, which is advantageous to the router or switch designed for hardware header processing;
(4) Enhanced support for the extension header and Options section, which, in addition to making the forwarding more efficient, but also for the future Network load new applications to provide adequate support;
(5) The use of flow tags allows us to provide personalized network services for the type of packet, and effectively guarantee the service quality of related services;
(6) Authentication and privacy: IPv6 IPSec as a necessary protocol to ensure the integrity and confidentiality of the end-to-end communication of the network layer;
(7) IPV6 has many improvements in mobile networks and real-time communication. In particular, unlike Ipv4,ipv6, which has a powerful automatic configuration capability, it simplifies system management for mobile hosts and LANs.

4. IPv4 to IPV6 transition technology

IPV6 cannot replace IPv4 immediately, so IPv4 and IPV6 will exist in a common environment for quite some time. A good conversion mechanism is required to provide a smooth conversion process that minimizes the impact on existing users. At present, this topic is the main goal of the IETF Ngtrans Working Group, and there are many conversion mechanisms that have been put forward, some of which have been used on 6Bone. The IETF recommends dual protocol stacks, tunneling techniques, and translation mechanisms such as NAT:

4.1 Ipv6/ipv4 Dual protocol Stack Technology

Simply put, the dual-stack mechanism is to enable the IPV6 network node to have a IPv4 stack and a IPv6 stack, while supporting IPV4 and IPV6 protocols. IPv6 and IPV4 are similar network layer protocols, both apply to the same physical platform and host the same transport layer protocol TCP or UDP, and if a host supports both the IPV6 and IPV4 protocols, the host can communicate with only those hosts that support IPV4 or IPV6 protocols, ipv6/ The protocol structure of the IPV4 dual protocol stack is as follows:

4.2 Tunnel Technology

Tunneling is the mechanism by which the IPV6 packet is encapsulated in the IPV4 packet as data, so that the IPV6 packet can be transmitted over the existing IPV4 infrastructure (mainly the IPV4 router). With the development of IPV6, there are some local IPv6 networks isolated by the backbone network running IPV4 protocol, in order to realize the communication between these IPV6 networks, tunneling technology must be adopted. Tunnel for the source site and the destination site is transparent, at the entrance of the tunnel, the router will IPV6 packet packets in the IPV4, the IPV4 packet source address and destination address respectively is the tunnel entrance and exit IPv4 address, at the exit of the tunnel, and then the IPV6 packet out forwarded to the destination site. The advantage of tunneling technology lies in the transparency of tunnels, the communication between IPV6 hosts can ignore the existence of tunnels, the tunnel only plays the role of physical channel. Tunnel technology is widely used in the early stage of IPV4 to IPv6 evolution. However, tunnel technology cannot implement communication between the IPV4 host and the IPV6 host.

4.3 Network Address Translation Technology

The network address translation (Translator,nat) technique is to treat IPV4 addresses and IPv6 addresses, respectively, as internal and global addresses, or vice versa. For example, when an internal IPV4 host communicates with an external IPV6 host, the server maintains a map of IPV4 and IPV6 addresses by transforming the IPV4 address (equivalent to the internal address) into a IPV6 address (equivalent to the global address) in the NAT server. Conversely, when an internal IPV6 host communicates with an external IPV4 host, the IPV6 host is mapped to an internal address, and the IPV4 host is mapped to a global address. NAT technology can solve the interoperability problem between IPV4 host and IPV6 host.

http://bt.byr.cn/

5. What are the common IPv6 resources?

• IPv6 List of common resources
• Bupt bupt Person: http://bt.byr.cn/
• Tohoku University Six-dimensional space: http://bt.neu6.edu.cn/
• Shanghai University Le bt:http://bt.shu6.edu.cn/
• North Speed Star pt:http://pt.bit6.edu.cn/login.php
• Chinese teacher Tau PT station: http://pt.scnu.edu.cn/
• Hua Shining Tau: https://bbs.scnu.edu.cn/
• bbs:http://bbs6.ustc.edu.cn/Nebula
• Drink from bbs:http://bbs6.sjtu.edu.cn/
• Bihaiqingtian bbs:http://bbs.dlut.edu.cn/
• IPv6 google:http://ipv6.google.com/or http://ipv6.google.co.jp/
• Shenzhen University six searches-ipv6 search: http://6sou.szu.edu.cn/ipv6/zh/
• TUNA Mirror Station of Tsinghua University: https://mirrors6.tuna.tsinghua.edu.cn/
• Communication University: http://ipv6.cuc.edu.cn
• IPV6 TV/Video
• Zhong Ke TV broadcast live: http://tv6.ustc.edu.cn/
• Tsinghua University iptv:https://iptv.tsinghua.edu.cn/
• Bupt man iptv:https://tv.byr.cn
• Tohoku University IPv6 Video: http://hdtv.neu6.edu.cn/
• The light and shadow Legend of Nankai University: http://movie.nankai.edu.cn/
• IPv6 Search/Navigation
• Shenzhen University six World: http://6world.szu.edu.cn/
• Shenzhen University six searches-ipv6 search: http://6sou.szu.edu.cn/ipv6/zh/
• Home of China IPv6 website: http://www.ipv6link.cn/

6. How do I confirm that my computer gets an IP address automatically?

Control Panel → Network and internet→ open Network and sharing center → change adapter settings → Double-click local connections → properties → Click Internet Protocol version 6 (Tcp/ipv6) → Verify that the IP address and DNS server address are automatically obtained → OK → close → close.

Reference website:

1. http://ipv6.pku6.edu.cn/ipv6intro.htm

2. http://ipv6.pku6.edu.cn/celuehtm.htm

3. http://ipv6.tsinghua.edu.cn/

Understanding and using IPV6