Introduction to over-technology of IPv6 and IPv4 networks

In IPv6 and IPv4 networks, we often use tunneling technology to connect the two links. The specific tunneling technology is divided into many types. Now we will make an analysis on this aspect. In the previous articles, we have already introduced knowledge about 6to4 and manual and automatic tunnel configuration. Now let's take a look at other technologies.

NAT-PT

Network Address Translation-protocol conversion (NAT-PT) is an IPv4/IPv6 Interoperability Technology, it can realize the intercommunication between pure IPv6 nodes and pure IPv4 nodes. The NAT-PT uses the gateway device to connect IPv6 and IPv4 networks. When IPv4 and IPv6 nodes access each other, NAT-PT gateway implements translation and address ing of the two protocols. NAT-PT gateway maintains an IPv4 address pool while working, NAT-PT gateway allows you to dynamically assign IPv4 addresses to nodes in an IPv6 network. It maintains address ing relationships and converts IPv4 and IPv6 protocols ｡

In order to ensure the correct operation of the NAT-PT, NAT-PT gateway and DNS application gateway need to be combined to ensure the correct resolution of cross-Network Address Resolution requests ｡

NAT-PT technology can better solve the problem of intercommunication between IPv4 and IPv6, most application-layer protocols can be interconnected without modification. However, for applications that need to transmit IP layer information in the control plane of the application-layer protocol, can not communicate through the Basic NAT-PT device. must be combined with the corresponding Application Layer Gateway (ALG) to achieve the conversion of these application layer protocols ｡

Other IPv4/IPv6 transition technologies

In addition to the above several technologies, there are many other IPv6 and IPv4 network transition technologies, which are not described in detail in this article. The following is only a brief description of the main technologies ｡

6over4 Tunnel

6over4 is an automatic tunnel technology. IPv6 hosts over 6 Use IPv4 multicast domains as the virtual link layer to achieve interconnection through IPv4 multicast ｡

ISATAP

ISATAP (Intra-SiteAutomaticFunnelAddressing Protocol) supports IPv6 hosts in the IPv4 subnet to access the IPv6 router through automatic tunnel. ISATAP uses the specific address format of the embedded IPv4 address: the 64-bit prefix + 32-Bit String ipv5efe + 32-bit IPv4 address. The ISATAP address can use the standard public IPv6 address prefix, IPv4 can be either a public address or a reserved address. ISATAP supports the reserved IPv4 address to connect IPv6 hosts in the IPv4 subnet of the NAT device ｡

Tunnel proxy

TunnelBroker automatically proxies Tunnel Configuration requests of IPv6 users in IPv4 networks to simplify tunnel configuration, the tunnel proxy and tunnel server are used. users who need IPv6 Access to the tunnel proxy respond to user requests, the tunnel server is a dual-stack device that is connected to IPv6 and IPv4 networks, it accepts the tunnel proxy configuration instructions and completes operations such as creating and removing tunnels between users ｡

MPLS tunnel

MPLS tunnel is connected to IPv6 through MPLSLSP in IPv4 networks. MPLS tunnel has multiple implementation methods, which are commonly used in the 6PE mode. The 6PE method has no requirements for CE devices on the user end, the PE device is a dual-stack device that supports the establishment of MPLS tunnels in IPv4 networks ｡

Application Conversion Technology

In the IPv4/IPv6 Interoperability Technology, in addition to the NAT-PT network conversion technology, there are some application layer conversion technology (including BIA, SOCK64, etc ), by modifying the application layer of the user system, these technologies convert IPv6 and IPv4 network requests at the application layer to achieve interoperation between IPv4 and IPv6 applications ｡