Re: [dhcwg] preliminary comments on draft-ietf-dhc-sedhcpv6-17

[Lishan Li <[e-mail]>]

2016-12-02 3:44 GMT+08:00 神明達哉 <[e-mail]>:

> At Thu, 1 Dec 2016 19:46:06 +0800,
> Lishan Li <[e-mail]> wrote:
>
> > > This didn't answer my question.  Could you first answer the question?
> > > If there's no such restriction in the base protocol, we cannot assume
> > > it and can't assume it in designing sedhcpv6.
> > >
> > [LS]: I just think that it is a default fact. Could you please give an
> > example that the client communicates with two DHCPv6 servers
> > for the address configuration in the same time?
>
> I don't have an example; I already noted it would be unlikely in
> practice.  My point is that unless the restriction is specified in the
> protocol we can't design a new protocol implicitly assuming that
> restriction.  Otherwise someone may deploy the service with violating
> the assumption, and we cannot blame them as it's invalid.  We should
> either:
> 1. design the protocol (=sedhcpv6) so it can work without the
>   assumption, or
> 2. explicitly state it's a restriction that this protocol assumes
>
> BTW, on thinking about the reconfigure case more, I realized that
> including a key tag option for the client public key in the Encrypted
> Reply is probably a bad idea, as it could be used for client-tracking.
> So, in the end, option #2 above may be the least bad option anyway.
> The assumed restriction wouldn't be that restrictive in practice, and
> the client can still try all possible key pairs (if it uses multiple
> pairs) in the rare corner cases.
>
[LS]: Agree. Then in this version, we adds the assumption description
clearly.

Best Regards,
Lishan