@jasontse 因为 Google 用的是 Cisco ASA 的标准，不代表 DNS64 的就必须用这个标准，可以用企业自己的前缀的。具体可以参考 DNS64 的 RFC： https://tools.ietf.org/html/rfc6147
The prefixes to be used as Pref64::/n and their applicability are
discussed in [RFC6052]. There are two types of prefixes that can be
used as Pref64::/n.

o The Pref64::/n can be the Well-Known Prefix 64:ff9b::/96 reserved
by [RFC6052] for the purpose of representing IPv4 addresses in
IPv6 address space.

o The Pref64::/n can be a Network-Specific Prefix (NSP). An NSP is
an IPv6 prefix assigned by an organization to create IPv6
representations of IPv4 addresses.
The main difference in the nature of the two types of prefixes is
that the NSP is a locally assigned prefix that is under control of
the organization that is providing the translation services, while
the Well-Known Prefix is a prefix that has a global meaning since it
has been assigned for the specific purpose of representing IPv4
addresses in IPv6 address space.
前缀可以用 64:ff9b::/96 也可以用企业自己的前缀。区别就是第二种是由企业控制的，而第一个全球通用。