Re: default-iids and stable addresses

[Tim Chown <[e-mail]>]

On 19 May 2016, at 02:49, Lorenzo Colitti <[e-mail]<mailto:[e-mail]>> wrote:

On Thu, May 19, 2016 at 3:09 AM, 神明達哉 <[e-mail]<mailto:[e-mail]>> wrote:
> As a co-author of draft-ietf-6man-default-iids, I just wanted to check
> that we're on the same page, because I have the feeling that the above
> keeps getting misinterpreted.

Misinterpretation (I'd call it confusion in this context, though) of a
document often happens because the document isn't clear enough

+1

I agree that it’s at best ambiguous.

Section 3 says:

"1. Do not result in any changes to the basic behavior of addresses

       generated via stateless address autoconfiguration [ADDRCONF<https://tools.ietf.org/html/rfc4941#ref-ADDRCONF>].


which implies that SLAAC still runs as normal, so you get a public address from that, and


2.  Create additional addresses based on a random interface
       identifier for the purpose of initiating outgoing sessions."

which implies the temporary address is *in addition* to the SLAAC-derived address, unless you hold the “Take some more tea Alice” view of additional.

Then 3.1 says:

"[ADDR_SELECT<https://tools.ietf.org/html/rfc4941#ref-ADDR_SELECT>] mandates implementations to provide a mechanism, which

   allows an application to configure its preference for temporary
   addresses over public addresses.“

which implies both are configured.

And then section 3.3 says the node MUST:

"Process the Prefix Information Option as defined in [ADDRCONF<https://tools.ietf.org/html/rfc4941#ref-ADDRCONF>]
either creating a new public address or adjusting the lifetimes

       of existing addresses, both public and temporary.“

So there’s a lot of text implying temporary addresses are used alongside public ones, and thus that ambiguity should be clarified.

But again I agree we should make it clear that that need not be the case.

Tim