Sparse IPv6 allocations
A request coming from a customer (see support#20158):
The cable operator are requesting that IA_NA address (/128) is taken for each customer from a different /64.
The use case asks for both address (IA_NA) and prefix (IA_PD).
In Kea's terms, there are couple factors:
- we could develop a hook for this that would overrule kea's lease6_select.
- we could implement new allocator that for PD would work as usual, but for IA_NA, it would look for allocated PD for this client and synthesize IPv6 address from it.