1, IPv6/IPv4 dual protocol stack technology?
The dual-stack mechanism enables IPv6 network nodes to have an IPv4 stack and an IPv6 stack, and support both IPv4 and IPv6 protocols. IPv6 and IPv4 are network layer protocols with similar functions, both of which are applied to the same physical platform and carry the same transport layer protocol TCP or UDP.
If a host supports both IPv6 and IPv4 protocols, it can communicate with a host that only supports IPv4 or IPv6 protocols.
2. Tunnel technology?
Tunnel mechanism is a mechanism that encapsulates IPv6 packets as data in IPv4 packets when necessary, so that IPv6 packets can be transmitted on the existing IPv4 infrastructure (mainly IPv4 routers). With the development of IPv6, some local IPv6 networks are isolated from the backbone network running IPv4 protocol. In order to realize the communication between these IPv6 networks, tunneling technology must be adopted.
The tunnel is transparent to the source site and the target site. At the entrance of the tunnel, the router encapsulates the IPv6 packet in IPv4, and the source address and destination address of the IPv4 packet are the IPv4 addresses at the entrance and exit of the tunnel respectively. At the exit of the tunnel, IPv6 packets are taken out and forwarded to the destination site.
3. Network address translation technology?
Network Address Translation (NAT) technology regards IPv4 address and IPv6 address as internal address and global address respectively, and vice versa. For example, when an internal IPv4 host wants to communicate with an external IPv6 host, an IPv4 address (equivalent to an internal address) is converted into an IPv6 address (equivalent to a global address) in the NAT server, and the server maintains a mapping table of IPv4 and IPv6 addresses.
Extended data:
Advantages and characteristics of IPv6:
1 and IPv6 have larger address spaces.
2.IPv6 uses a smaller routing table.
3.IPv6 adds enhanced multicast support and flow control.
4.IPv6 adds support for automatic configuration.
5.IPv6 has higher security.
6.IPV6 allows extension of this protocol.
7.IPV6 uses a better header format.
8.IPV6 has some new options to implement additional functions.
Baidu Encyclopedia -IPv6