Subject: RE: Node Req: Issue31: DHCPv6 text (ignore previous mails)

From: [email-masked]
Date: Thu, 20 Nov 2003 14:50:19 -0500

> to:
> 
>    Nodes that implement DHCP MUST use DHCP upon the receipt of a 
>    Router Advertisement with the 'M' flag set (see section 5.5.3 of 
>    RFC2462).  In addition, in the absence of a router,
>    IPv6 Nodes that implement DHCP MUST attempt to use DHCP.  In this 
>    context, 'use DHCP' means trying to obtain both address(es) and 
>    other configuration information through DHCP.

This wording seems clumsy to me.  How about:

If no Router Advertisements are recieved within (NN seconds?) of
joining a link and sending a Router Solicitation, IPv6 hosts that
implement DHCPv6 should attempt to use DHCPv6 to obtain both
IPv6 address(es) and other configuration information.  [Do we
need to say what happens if a router advertisement is received
later?]

Upon receipt of a router advertisement with the 'M' flag set (see
section 5.5.3 of RFC 2462), IPv6 hosts that implement DHCPv6 MUST attempt 
to use DHCPv6 to obtain both IPv6 addess(es) and other configuration
information.

> to:
> 
>    IPv6 Nodes (acting as hosts) that implement DHCP, MUST use 
> DHCP upon 
>    the receipt of a Router Advertisement with the 'O' flag set (see 
>    section 5.5.3 of RFC2462).  In addition, in the
>    absence of a router, hosts that implement DHCP MUST attempt to use
>    DHCP. In this context, 'use DHCP' means trying to obtain 
> only other 
>    configuration information through DHCP, not address(es).
> 
>    IPv6 Nodes that do not implement DHCP can ignore the 'O' flag 
>    of a Router Advertisement.  Furthermore, in the absence of
>    a router, these types of node are not required to initiate DHCP.

Similarly, how about:

"Upon reciept of a Router Advertisement with the 'O' flag set (see
section 5.5.3 of RFC 2462), IPv6 hosts that implement DHCPv6 MUST
attempt to use DHCPv6 to obtain non-address configuration information,
but not IPv6 address(es). 

IPv6 nodes that do not implement DHCPv6 client functionality should
ignore the 'M' and 'O' bits of the router advertisement."

The no router case shouldn't be repeated here, as it is covered
above.  And, yes, I do think that hosts should attempt to use
DHCPv6 to get IPv6 addresses in the absence of a router.  Also, I 
think it is silly to say that hosts that don't implement DHCPv6 
don't need to use it...

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From: Tim Chown <[email-masked]>
Date: Thu, 20 Nov 2003 21:33:02 +0000

> to use DHCPv6 to obtain both IPv6 addess(es) and other configuration

Well, section 5.5.3 says "should invoke" (lower case) not MUST....?

[Aside:
What was the thinking behind the M bit meaning "address and other info",
and the O bit "other info" - would it not have been cleaner for M to
mean "address info" and O to mean "other info"?   Just curious as to why
it was done that way...]

Tim

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From: Pekka Savola <[email-masked]>
Date: Fri, 21 Nov 2003 16:03:45 +0200 (EET)

> need to say what happens if a router advertisement is received

While getting a better specification to the "no RA/Router" case would 
be useful, this is probably the wrong place to do it.

(In general I agree that my rewording attempts were a bit wrong, but 
they brought up the point about the need to for more precise 
wording..)

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings