Subject: WG ACTION: ACCEPT [LL41] Broadcast text for IPv4 LL

From: Erik Guttman <[email-masked]>
Date: Tue, 30 Mar 2004 17:27:07 +0200 (MEST)

Action: Accept the change.

LL41

Description of Issue: Broadcast text for IPv4 LL
Submitter Name:       Bill Fenner & Margaret Wasserman
Submitter Email:      
Date submitted:       Feb 20, 2004
Reference:            
(T=tech, E=edit):     T
Priority (S must, 1 Should, 2 May fix): 1
Section:               2.6.2
Rationale/Explanation: 

Bill Fenner wrote:
2.6.2 says

  ...if the destination address is in the
  169.254/16 prefix (including the 169.254.255.255 broadcast address),
  then the sender MUST ARP for the destination address and then send
  its packet directly to the destination on the same physical link.

This sounds like it's saying that 169.254.255.255 is not to be treated
as a broadcast address, but it describes it as "the .. broadcast
address".  Potentially confusing.

This is not a DISCUSS because this is a relatively minor issue in a
document that I don't want to prevent from moving forward, but if it
is going to be spun for something else (or even if this can be handled
in AUTH48) I'd be happier.

Margaret Wasserman wrote:

  In section 2.6.2 "Forwarding Rules", the document says:

  "Whichever interface is used, if the destination address is in the
  169.254/16 prefix (including the 169.254.255.255 broadcast address),
  then the sender MUST ARP for the destination address and then send
  its packet directly to the destination on the same physical link.
  This MUST be done whether the interface is configured with a Link-
  Local or a routable IPv4 address."

      I don't think that the above paragraph is intended to indicate
      that an ARP should be sent for every link-local packet, but
      it could be read that way.  In particular, it doesn't seem
      correct to ARP for a broadcast address.  Also, it should be
      okay (AFAIK) to use a normal ARP cache for these addresses,
      right?

Long Description:
Proposed Change:

Omit 'broadcast address' in the text above - which becomes:

  ...if the destination address is in the
  169.254/16 prefix (excluding the address 169.254.255.255, which is
  the broadcast address for the Link-Local prefix), then the sender 
  MUST ARP for the destination address and then send its packet 
  directly to the destination on the same physical link.