Subject: WG consensus action - 1 week to discuss [LL1] Preferred use of configured to v4 LL address

From: Erik Guttman <[email-masked]>
Date: Mon, 17 Feb 2003 17:59:20 +0100

Please discuss this issue in the next week.  Our goal is to achieve
WG consensus.  Please try to stay on-topic during the discussion.

See also http://www.spybeam.org/ll1.html

We should strive to conclude this discussion by Feb 24.

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Description of Issue  Preferred use of configured to v4 LL address 
Submitter Name  Erik Guttman
Submitter Email Address  [email-masked]
Date first submitted  6 Feb 2003
Reference  http://www.merit.edu/mail.archives/zeroconf/2003-01/msg00262.html
http://www.merit.edu/mail.archives/zeroconf/2003-01/msg00548.html
http://www.merit.edu/mail.archives/zeroconf/2003-02/msg00000.html 
Comment Type ['T'echnical | 'E'ditorial] T
Priority ['S' Must fix | '1' Should fix | '2' May fix ] S
Section 1.5
Rationale/Explanation of issue:

Supporting multiple address per interface, where one address is v4 LL 
and other addresses are configured leads to a scoped address problem. 
Hosts must select which source address to send datagrams with from that 
interface. In addition, application considerations are much more complex 
when there are multiple scopes in which the application must operate in.

Lengthy description of problem:

A lot of the programming issues arise from having multiple addresses of 
different scope for the same hosts -- there was an extensive debate on 
that point in the IPv6 WG. If a global address is available, using just 
that address has a number of good properties -- as in, it does not break 
existing applications. So, there is a strong incentive to not configure 
a LL address when a global address is available, either through static 
configuration or through DHCP. [Christian Huitema]

Requested Change: A host should use an IPv4LL address as a source 
address when the only addresses available to the host are IPv4LL addresses.

Otherwise, a host SHOULD NOT use an LL source address unless the 
application has unambiguously requested this.

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From: Keith Moore <[email-masked]>
Date: Mon, 17 Feb 2003 15:16:49 -0500

I support LL1.