Introduction to IPv6 transition solutions in China

In the gradual replacement of IPv6 networks, most of our internet users still use IPv4. This leads to a topic: how can we achieve perfection? Now let's take a look at the IPv6 transition solution based on this question. Let's take a look at the following content.

IPv6 transition scheme features in China

In the conception of the transition phase of IPv6, it is generally believed that the first occurrence will be many small-scale experimental IPv6 networks, which are connected through tunnels in IPv4, therefore, many tunnel interconnection technologies have been developed. because China has invested money to build a CNGI Network Based on IPv6 technology, China's IPv6 development will go beyond the above stages ｡

Once CNGI is built, China will form a large-scale IPv6 backbone network covering a wide range of areas, and backbone network nodes are directly connected through IPv6 circuits. Therefore, tunneling technology will not be used in backbone networks, various tunnels are mainly used to access users and application sites ｡

Although a large-scale network is built, but the initial application of IPv6 is not much, so we must consider IPv6 and the existing IPv4 mutual access. operators need to deploy NAT-PT and other network protocol conversion equipment in the network ｡

Therefore, China's IPv6 transition scheme will mainly involve the user access scheme and network interconnection scheme ｡

User Access Solution

In the future, Internet users will be primarily broadband access users. For large-scale pure IPv6 Access, special access servers need to be deployed by operators, through PPPoE and other methods to achieve broadband user access. The access server can directly allocate IPv6 addresses to users. For cities with CNGI nodes, the access server can use a direct connection circuit to access the CNGI Gateway Router, complete user access. For cities without CNGI nodes or with no direct connection circuit, the access server can connect to the CNGI Access Router through the existing IPv4 network tunnel. In this case, the tunnel can be manually configured, such as tunnel or MPLS. Operators with IPv4 access resources can also consider IPv4 access Network transformation, this allows the existing IPv4 access server to access IPv6 users. The access server should be able to allocate different types of addresses based on user authentication conditions, and support creating tunnels to connect IPv6 users to the backbone network ｡

For the application site, if there is no physical connection to access IPv6, it can be connected through IPv4 network in tunnel mode. tunnel mode such as manual configuration of tunnel and MPLS is also suitable ｡

Temporary access to dual-stack users in IPv4 networks and some enterprise subnets in IPv4 networks, it is suitable to use 6to4 tunnel, tunnel proxy, ISATAP, etc. In order to achieve the access of such users, operators should set up tunnel proxy, tunnel server, 6to4 relay router and other equipment to facilitate the access ｡

Network Interconnection IPv6 transition plan

In the current IPv4/IPv6 Interoperability Technology, NAT-PT is a mature network protocol conversion technology. The operator can use NAT-PT to achieve the interconnection between IPv6 network and IPv4 network. Through the device to connect IPv6 network and IPv4 network, with the DNS-ALG settings, most internet services can be interconnected ｡

You can consider either of the following two ways to set the location of the NAT-PT Gateway:

A) set up a small number of devices on the main nodes of the IPv6 backbone network to achieve traffic intercommunication between the two networks. In this way, the investment in devices is small, but the traffic in the network will generate non-optimized routes, and when the business volume is large, high business pressure on NATPT gateway and high requirement on device performance ｡

B) The operator sets up a NAT-PT gateway in each IPv6 Metropolitan Area Network to interconnect with IPv4 networks in the Metropolitan Area Network ｡

Operators can choose different configuration schemes based on different periods of network development ｡