1. log 那里 topic: dhcp, dest: memory ，打一下 ros 的 dhcp 包看一下
2. RFC3633: https://datatracker.ietf.org/doc/html/rfc3633

> The requesting router subnets the delegated prefix and assigns the
longer prefixes to links in the subscriber's network. In a typical
scenario based on the network shown in Figure 1, the requesting
router subnets a single delegated /48 prefix into /64 prefixes and
assigns one /64 prefix to each of the links in the subscriber
network.
> An IA_PD is a construct through which a delegating router and a
requesting router can identify, group and manage a set of related
IPv6 prefixes.

成都电信我没记错只给了 /64 ，我现在换了其他运营商了，印象中 PD 是不能继续再分了。

供参考。