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 ________________________________ -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 -------------------------------------------------------------------- -- ===================================================================== Josh Littlefield Cisco Systems, Inc. [EMAIL PROTECTED] 1414 Massachusetts Avenue tel: 978-936-1379 fax: 978-936-2226 Boxborough, MA 01719-2205
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