Thanks, Julien. This is a good data point. DO you know if the network has NAT 
devices, that also respond to the router discovery messages?

regards,
suresh

--- On Tue, 10/14/08, Julien Laganier <[EMAIL PROTECTED]> wrote:

> From: Julien Laganier <[EMAIL PROTECTED]>
> Subject: Re: [Int-area] [BEHAVE]  WGLC: draft-ietf-behave-nat-icmp-09
> To: [email protected], [EMAIL PROTECTED]
> Cc: "Behave WG" <[EMAIL PROTECTED]>, "Fernando Gont" <[EMAIL PROTECTED]>, 
> [EMAIL PROTECTED]
> Date: Tuesday, October 14, 2008, 4:07 AM
> Suresh,
> 
> FWIW, I've seen ICMP router discovery being used
> extensively in at least 
> one large managed network.
> 
> --julien
> 
> On Monday 13 October 2008, Pyda Srisuresh wrote:
> > Folks,
> >
> > The "Router advertisements and
> solicitations" message appears to be
> > rarely used in Ipv4 networks. Please let me know if
> anyone has
> > objections to changing the requirement for this
> message to MAY from
> > MUST for NATs. If I dont hear any objection, I will
> convert this to
> > MAY in the next rev of the draft.
> >
> > Thanks.
> >
> > regards,
> > suresh
> >
> > --- On Wed, 10/8/08, Pyda Srisuresh
> <[EMAIL PROTECTED]> wrote:
> > > From: Pyda Srisuresh <[EMAIL PROTECTED]>
> > > Subject: Re: [BEHAVE] [Int-area] WGLC:
> > > draft-ietf-behave-nat-icmp-09 To: "Behave
> WG" <[EMAIL PROTECTED]>,
> > > "'Internet Area'"
> <[email protected]>, "Fernando Gont"
> > > <[EMAIL PROTECTED]> Cc:
> [EMAIL PROTECTED]
> > > Date: Wednesday, October 8, 2008, 10:49 PM
> > > --- On Wed, 10/8/08, Fernando Gont
> > >
> > > <[EMAIL PROTECTED]> wrote:
> > > > From: Fernando Gont
> <[EMAIL PROTECTED]>
> > > > Subject: Re: [BEHAVE] [Int-area] WGLC:
> > >
> > > draft-ietf-behave-nat-icmp-09
> > >
> > > > To: [EMAIL PROTECTED], "Behave
> WG"
> > >
> > > <[EMAIL PROTECTED]>, "'Internet
> Area'"
> > > <[email protected]>
> > >
> > > > Cc: [EMAIL PROTECTED]
> > > > Date: Wednesday, October 8, 2008, 5:37 PM
> > > > Hello, Pyda,
> > > >
> > > > Comments in-line...
> > > >
> > > > > > >    REQ-9: A NAT device MAY
> implement a
> > > >
> > > > policy control
> > > >
> > > > > > that prevents
> > > > > >
> > > > > > >    ICMP messages being
> generated toward
> > > >
> > > > certain
> > > >
> > > > > > interface(s).
> > > > > >
> > > > > > >    Implementation of such a
> policy
> > >
> > > control
> > >
> > > > overrides
> > > >
> > > > > > the MUSTs in
> > > > > >
> > > > > > >    REQ-10.
> > > > > >
> > > > > > Then.... shouldn't the
> requirements be
> > > > > > "SHOULD"s rather than
> > > >
> > > > "MUST"s?
> > > >
> > > > >[suresh] Essentially, the objective is
> not to
> > >
> > > dilute
> > >
> > > > the MUST or
> > > >
> > > > >SHOULD requirement on the NAT device,
> but to give
> > >
> > > the
> > >
> > > > device admin
> > > >
> > > > >an override capability. So, if the admin
> chooses
> > >
> > > to
> > >
> > > > enforce local
> > > >
> > > > >policies to override NAT operation, then
> the NAT
> > >
> > > device
> > >
> > > > MAY enforce
> > > >
> > > > >the local policy control. Would the
> following
> > >
> > > revised
> > >
> > > > wording work for you?
> > > >
> > > > >Implementation of such a policy control
> overrides
> > >
> > > the
> > >
> > > > MUSTs and
> > > >
> > > > >SHOULDs in REQ-10.
> > > >
> > > > Any would work for me. I was just wondering
> if it was
> > > > correct (from a
> > > > the perspective of RFC2119) to include a
> MUST that
> > >
> > > could be
> > >
> > > > overiden.
> > > > That is, I was wondering if that means that
> the
> > > > "requirements" should
> > > > be a "SHOULD" rather than a
> > >
> > > "MUST".
> > >
> > > > > > >           5. Router
> Advertisement and
> > > >
> > > > Solicitations,
> > > >
> > > > > > as described in
> > > > > >
> > > > > > >              Section 4.3.3.10
> of
> > >
> > > [RFC1812].
> > >
> > > > > > Does anybody actually use these
> ICMPv4
> > >
> > > messages?
> > >
> > > > I do
> > > >
> > > > > > recall Windows
> > > > > > systems sending these messages
> when they are
> > > >
> > > > bootstrapped,
> > > >
> > > > > > but...
> > > > >
> > > > >[suresh] If the WG believes any of these
> ought to
> > >
> > > be
> > >
> > > > obsoleted for
> > > >
> > > > >NAT devices, one option would be to
> dilute the
> > > >
> > > > requirement to MAY
> > > >
> > > > >for NATs in this document. However, we
> need to
> > >
> > > provide
> > >
> > > > sufficient
> > > >
> > > > >justification for any deviation for NATs
> from RFC
> > >
> > > 1812.
> > >
> > > > While these messages are a "MUST"
> in
> > >
> > > RFC1812, my
> > >
> > > > take is that RFC1812
> > > > is outdated in this respect, and that we
> should not
> > > > *require* them
> > > > for NATs. I'm not saying we should
> obsolete these
> > > > messages here (it
> > > > would be out of the scope of the document),
> but rather
> > >
> > > that
> > >
> > > > we should
> > > > not require NATs to support these messages
> that nobody
> > > > (that I know
> > > > of) is depending on.
> > >
> > > [suresh] Agreed. Do you suggest diluting both of
> the below
> > > MUSTs into MAY for NATs.
> > >
> > >           3. Parameter Problem Message,
> > >           5. Router Advertisement and
> Solicitations
> > >
> > > > > > >        b. MAY support:
> > > > > > >           1. Redirect
> Message, as
> > >
> > > described
> > >
> > > > in Section
> > > >
> > > > > > 4.3.3.2 of
> > > > > >
> > > > > > >              [RFC1812],
> > > > > >
> > > > > > If anything, I'd add that
> support should
> > > >
> > > > default to
> > > >
> > > > > > "off".
> > > > >
> > > > >[suresh] RFC1812 already has MAY
> requirement on
> > >
> > > this
> > >
> > > > and doesnot
> > > >
> > > > >mandate this. RFC 1812 says:
> > > >
> > > > MAYs are less of a concern to me (as they
> give you the
> > > > option to
> > > > support them, but do not require you to).
> > >
> > > [suresh] OK.
> > >
> > > > >    Contrary to [INTRO:2], a router MAY
> ignore
> > >
> > > ICMP
> > >
> > > > Redirects when
> > > >
> > > > >    choosing a path for a packet
> originated by the
> > > >
> > > > router if the router
> > > >
> > > > >    is running a routing protocol or if
> forwarding
> > >
> > > is
> > >
> > > > enabled on the
> > > >
> > > > >    router and on the interface over
> which the
> > >
> > > packet
> > >
> > > > is being sent.
> > > >
> > > > My take here is that the spirit f RFC1812 is
> that you
> > >
> > > can
> > >
> > > > discard
> > > > redirects *if* you are running a routing
> protocol
> > >
> > > (i.e.,
> > >
> > > > you're
> > > > knowledgeable about routing). However, it
> would be
> > >
> > > insane
> > >
> > > > to honor
> > > > redirects nowadays.... unless you're
> enforcing
> > > > something like GTSM
> > > > (the TTL hack). If not, basically anybody
> could DoS
> > >
> > > you by
> > >
> > > > sending
> > > > you a forged ICMP redirect.
> > > >
> > > > In anycase, as I said above, given that this
> is a MAY
> > >
> > > in
> > >
> > > > your
> > > > document, no changes are needed (i.e., you
> are not
> > > > mandating support
> > > > for redirects).
> > >
> > > [suresh] Right.
> > >
> > > > > > >           4. Address Mask
> Request/Reply
> > > >
> > > > Message, as
> > > >
> > > > > > described in
> > > > > >
> > > > > > >              Section 7.4 of
> this
> > >
> > > document.
> > >
> > > > > > AFAIK, these messages are not used
> in
> > >
> > > practice
> > >
> > > > (even when a
> > > >
> > > > > > number of
> > > > > > systems support them).
> Shouldn't they be
> > > >
> > > > deprecated as
> > > >
> > > > > > with the
> > > > > > information request/response?
> > > > >
> > > > >[suresh] I believe, It is not in the
> scope of this
> > > >
> > > > document to
> > > >
> > > > >deprecate ICMP messages or their use
> outside of
> > >
> > > NATs.
> > >
> > > > >For this reason, the requirement for
> Address mask
> > > >
> > > > request/Reply
> > > >
> > > > >support for NATs is diluted to MAY (from
> MUST in
> > >
> > > RFC
> > >
> > > > 1812).
> > > >
> > > > Same here. I have no real concerns here.
> > >
> > > [suresh] OK.
> > >
> > > Regards,
> > > suresh
> > >
> > > > Kind regards,
> > > >
> > > > --
> > > > Fernando Gont
> > > > e-mail: [EMAIL PROTECTED] ||
> [EMAIL PROTECTED]
> > > > PGP Fingerprint: 7809 84F5 322E 45C7 F1C9
> 3945 96EE
> > >
> > > A9EF
> > >
> > > > D076 FFF1
> > >
> > > _______________________________________________
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> >
> > _______________________________________________
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> 
> 
> 
> -- 
> --julien
> 
> [ New email address: [EMAIL PROTECTED] ]
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