RE: Route Information Options in Redirect Messages (updated)

["Templin, Fred L" <[e-mail]>]

Hi Jinmei-san,

> -----Original Message-----
> From: [e-mail] [mailto:[e-mail]] On Behalf Of ????
> Sent: Thursday, February 09, 2017 10:27 AM
> To: Templin, Fred L <[e-mail]>
> Cc: james woodyatt <[e-mail]>; IPv6 List <[e-mail]>
> Subject: Re: Route Information Options in Redirect Messages (updated)
> 
> At Tue, 7 Feb 2017 18:43:12 +0000,
> "Templin, Fred L" <[e-mail]> wrote:
> 
> > > BTW, if this proposal keeps the concept of "unsolicited redirect" and
> > > also allows the destination address of '::' to bypass the host's
> > > validity check of whether it's really the first hop router for the
> > > destination,
> >
> > No, that is not what we want to have happen. The document doesn't
> > say this currently, but we want to retain a revised version of the validity
> > check. The revised version of the check would say:
> >
> > OLD:
> >       - The IP source address of the Redirect is the same as the current
> >         first-hop router for the specified ICMP Destination Address.
> >
> > NEW:
> >       - The IP source address of the Redirect is the same as the current
> >         first-hop router for the specified ICMP Destination Address, or
> >         (when the ICMP Destination Address is '::') the same as the current
> >         first-hop router for the specified RIOs
> >
> > Would welcome better wording than this, but we definitely do want
> > to retain the validity check. Comments?
> 
> Okay, I now understand the intent.  In that case I think the
> validation logic (currently described in Section 3.1) will have to be
> more detailed.  It will also have to cover some corner cases such as
> where some of RIOs contain pass the above validation but some others
> don't.

I would rather have the validation check say that, if any of the RIOs
(among possibly multiple) fail the check then the entire Redirect
message also fails the check.

> Similarly, I guess it should specify which RIOs can be
> accepted by the receiving host in general (e.g., when the destination
> address is 2001:db8:a::1, should the host accept an RIO for
> 2001:db8:b::/48?).

To avoid this ambiguity, I would prefer to require that the destination
address MUST be set to "::" IFF any RIOs are included. That way,
legacy implementations that don't understand RIOs will reject the
Redirect because it doesn't include a valid destination address, while
new implementations will process the Redirect by ignoring the
destination address and parsing all included RIOs.

Thanks - Fred
[e-mail]

> --
> JINMEI, Tatuya