enable/disable temporary IPv6 per prefix

[Oliver Mangold]

Hi,

I have a question as a relatively new user to IPv6. I am wondering if it 
is currently possible to enable/disable the usage of temporary addresses 
on a per-prefix basis. My current understanding is that the feature is 
enabled by the the 'use_tempaddr' sysctl attribute, which is 
per-interface. What I would like to do is disable temp addresses for ULA 
prefixes. Did I miss something and this can already be done, or is it a 
feature planned for the future, maybe? RFC4941 seems to agree that this 
is a valid use case:


Additionally, sites might wish to selectively enable or disable the use 
of temporary addresses for some prefixes.  For example, a site might 
wish to disable temporary address generation for "Unique local" [ULA] 
prefixes while still generating temporary addresses for all other global 
prefixes.  Another site might wish to enable temporary address 
generation only for the prefixes 2001::/16 and 2002::/16, while 
disabling it for all other prefixes. To support this behavior, 
implementations SHOULD provide a way to enable and disable generation of 
temporary addresses for specific prefix subranges.  This per-prefix 
setting SHOULD override the global settings on the node with respect to 
the specified prefix subranges.  Note that the pre-prefix setting can be 
applied at any granularity, and not necessarily on a per-subnet basis.


Best regards,

Oliver