Re: [DNA] MUST NOT add DNA Option when landmark RA = NO?(draft-pentland-dna-protocol-00.txt)

[Brett Pentland <brett.pentland@eng.monash.edu.au>]

MUST NOT is probably too strong.  SHOULD NOT or even MAY NOT
might be ok.  I don't think there's much value
in the DNA option in this case, because the host cannot use the
prefixes in it for configuration. Those same prefixes
should arrive in PIOs in RAs from the router(s) where they are
explicitly configured, very soon anyway.

Brett.

Greg Daley wrote:
> I'm confused by this statement in the draft:
> 
> In Section 5.1.4:
> 
> "... If the RS contains a Landmark Option whose prefix does not
>  match any of those in the interface's stored prefix list, then
>  the Landmark option with the Landmark prefix is included in the
>  RA but with the No flag set.  All fixed options (MTU,
>  Advertisement Interval, flags, etc.) are added to the Router
>  Advertisement.  Prefix Information Options for any explicitly
>  configured prefixes SHOULD be added to the Router
>  Advertisement, while the DNAO for learned prefixes MUST not be
>  added."
> 
> Is there a reason why DNAO MUST NOT be sent in this case?
> 
> Isn't it useful to indicate immediately which of the
> prefixes are available on the new link?
> 
> Greg