Thanks Josh. That is the point of our drafts is to clarify that default
behavior is off-link because that mode maps to sending data to the
default router. The ND RFC is also loose by saying send data to the
router when the RFC should say send all non-link-local traffic to the
default router.
In hind sight, it made sense for us to have blocked RFC 4861 in AUTH48
state when we were commenting on 2461bis-11 and 24628.
Hemant
________________________________
From: Josh Littlefield (joshl)
Sent: Wednesday, December 05, 2007 11:08 AM
To: Hemant Singh (shemant)
Cc: Suresh Krishnan; [EMAIL PROTECTED]; IETF IPv6 Mailing List
Subject: Re: Here is the reference to 6.3.4 text that is ambigious text
It is not crystal clear, but my impression is that this paragraph is
saying:
Default sending behavior is send to default router.
Reception of L=1 signals on-link (can use ND to send directly)
Reception of L=0 is no-op.
Because L=0 is no-op, if one considered the prefix on-link due to prior
L=1, then prefix is still on-link.
If one did not consider the prefix on-linke due to prior L=1, then
retain default behavior.
It might be clearer to have said that default assumption is that all
prefixes are off-link, and this means send to default router. Only
reception of L=1 can change that for any specific prefix. A prefix with
L=0 does not change off-link, or on-link status of prefix, and is the
same as omitting the prefix entirely from the RA, from the point of view
of on-link determination.
Hemant Singh (shemant) wrote:
The summary from this section snipped from 6.3.4 of RFC 4861 is
saying no on-ink information does not mean off-link. So why is the text
is red where is says, send traffic to default router being said because
the text in red signals off-link behavior. Why is this paragraph not
ambiguous?
Prefix Information options that have the "on-link" (L) flag set
indicate a prefix identifying a range of addresses that
should be
considered on-link. Note, however, that a Prefix Information
option
with the on-link flag set to zero conveys no information
concerning
on-link determination and MUST NOT be interpreted to mean
that
addresses covered by the prefix are off-link. The only way
to cancel
a previous on-link indication is to advertise that prefix
with the
L-bit set and the Lifetime set to zero. The default behavior
(see
Section 5.2) when sending a packet to an address for which no
information is known about the on-link status of the address
is to
forward the packet to a default router; the reception of a
Prefix
Information option with the "on-link" (L) flag set to zero
does not
change this behavior. The reasons for an address being
treated as
on-link is specified in the definition of "on-link" in
Section 2.1.
Prefixes with the on-link flag set to zero would normally
have the
autonomous flag set and be used by [ADDRCONF].
Hemant
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