WG ACTION: ACCEPT [LL43] Clarify rules for use of LL vs routeable addresses

Action: Accept the change below.

LL43

Description of Issue: Clarify rules for use of LL vs routeable addresses
Submitter Name:       Ted Hardie
Submitter Email:      
Date submitted:       20 Feb 04
Reference:            
(T=tech, E=edit):     T
Priority (S must, 1 Should, 2 May fix): S
Section:               1.4
Rationale/Explanation: 
Long Description:
The draft has the following text in section 1.4:

  a. Routable addresses should be used within applications whenever
  they are available.

  b. Names that are globally resolvable to routable addresses should be
  used within applications whenever they are available.  Names that are
  resolvable only on the local link (such as through use of protocols
  such as Link Local Multicast Name Resolution [LLMNR]) MUST NOT be
  used in off-link communication.  IPV4 addresses and names which can
  only be resolved on the local link SHOULD NOT be forwarded, they
  SHOULD only be sent when a Link-Local address is used as the source
  address.  This strong advice should hinder limited scope addresses
  and names from leaving the context in which they apply.

  c. Link-Local IPv4 addresses MUST NOT be configured in the DNS.

A & B seem to contain contrary advice (Use routable addresses in
applications vs.  use names resolvable to routable addresses in
applciations); this is probably because the authors see an "instead"
in here that isn't stated.  I'd suggest rephrasing A.  I'd also
suggest reversing the order so that C is first (it is the MUST here),
B's advice is next (It is the SHOULD), and then the current A is "If
names resolvable to globally routable addresses are not available, but
the globally routable addresses are, they should be used instead of
link-local addresses".

Proposed Change:

Replace a-c in 1.4 with

  a. Link-Local IPv4 addresses MUST NOT be configured in the DNS.

  b. If names resolvable to globally routable addresses are not 
  available, but the globally routable addresses are, they should 
  be used instead of link-local addresses
  
  c. Names that are globally resolvable to routable addresses should be
  used within applications whenever they are available.  Names that are
  resolvable only on the local link (such as through use of protocols
  such as Link Local Multicast Name Resolution [LLMNR]) MUST NOT be
  used in off-link communication.  IPV4 addresses and names which can
  only be resolved on the local link SHOULD NOT be forwarded, they
  SHOULD only be sent when a Link-Local address is used as the source
  address.  This strong advice should hinder limited scope addresses
  and names from leaving the context in which they apply.