IPv6 Transition Policy / IPv6 过渡策略

2025/02: All IPv6 Transition steps have been completed and our backbone network is now in full IPv6-only operation.

2025/02: 所有 IPv6 Transition 步骤均已完成，现在我们的主干网络处于完全仅 IPv6 操作模式。

Dear users, ISPs and stakeholders:

IANA's IPv4 resources have been exhausted, and although nearly half of DN42's IPv4 resources remain, the overall shift to IPv6 on the Internet is a general trend.

Therefore, under our repeated consideration, we decided to completely terminate IPv4 content services in 2021 and only retain IPv4 Transit services. At the same time, considering compatibility, we will consider cooperating with services such as 464XLAT and NAT64 to continue to provide customers with the IANA network IPv4 access in.

The entire migration plan will be divided into three steps:

1. Before Jan, we will ensure that every service provided is reachable with IPv6 and will abolish some IPv4 services.

2. Before Feb, we will resolve all domain names only to IPv6 addresses, and abolish IPv4 authoritative and recursive DNS.

3. Before March, we will deploy IANA's 464XLAT service, stop the announcement of DN42 IPv4, and completely terminate the provision of DN42 IPv4 access to customers.

During the transfer process, the service may be abnormal or inaccessible, please understand. The application and promotion of IPv6 are inseparable from your support and cooperation.

尊敬的用户、ISP 和利益相关方：

IANA 的 IPv4 资源已然枯竭，而 DN42 的 IPv4 资源虽然还有近半数的剩余，互联网全面转向 IPv6 已是大势所趋。

因而，在我们的再三考虑之下，决定于 2021 年内全面终止 IPv4 的内容服务，仅保留 IPv4 Transit 服务，同时，考虑到兼容性，我们将考虑配合 464XLAT 和 NAT64 等服务，继续为客户提供 IANA 网络中的 IPv4 访问。

整个迁移计划将分为三步：

1. 在 1 月前，我们将保证提供的每项服务均可 IPv6 可达，并废除部分 IPv4 服务。

2. 在 2 月前，我们将会把所有域名仅解析到 IPv6 地址，并废止 IPv4 权威和递归 DNS。

3. 在 3 月前，我们会部署好 IANA 的 464XLAT 服务，停止 DN42 IPv4 的宣告，并完全终止对客户提供 DN42 IPv4 访问。

在转移过程中，服务可能会出现异常或无法访问的情况，请谅解。IPv6 的应用和推广离不开各位的支持与配合。