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Re: M & O Bits was: draft-ietf-ipv6-node-requirements-01.txt

"Fred L. Templin" <ftemplin@iprg.nokia.com> writes:

> I'm still of the opinion that some ambiguity exists. Namely, if a prefix
> option has the Autonomous flag ("A" bit) set and the on-link flag ("L" bit)
> NOT set, one could infer from reading RFC 2462, section 5.5 that it is OK
> to go ahead and configure an address from the (off-link) prefix as specified
> in 5.5.3 d).

Good, as that is the intended behavior.

> But then, which link would one derive an interface identifier
> from in order to form an address? (And, which interface would one assign
> the address to?)

This question applies to any address a node autoconfigures, regardless
of the setting of the L-bit. The scope of the advertisement of course
applies to the interface on which it receives.

It's not that surprising to me that the wording on the L-bit still
seems odd. My recollection is that the exact wording you have been
quoting was put in explicitely because the previous wording was even
more confusing. :-)

The whole point is that if the A bit is set, you do the processing
associated with generating an address. To do this, you don't need to
know whether the prefix is considered on-link or not. Likewise, the
list of prefixes to consider on-link is independent of any addresses
you may (or may not) have configured. They are two logically
orthogonal issues.

I still do not (yet) see the need for further clarifications in the
documents (and certainly not in node requirements, for the level of
detail we're talking about here).

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