Subject: LL17 (also LL1 and LL26)

From: "Philip Nye" <[email-masked]>
Date: Tue, 11 Feb 2003 18:43:17 -0000

I accept the principle of LL17 but not the text.

The existing text is confusing because its use of "MAY choose to ARP"
suggests that the host has an alternative to send the packet elsewhere. In
practice sending to a router is expressly forbidden in the same section and
the only alternative is to drop the packet. I don't think we can forbid this
so changing the MAY to a MUST is not appropriate.

The text proposed in LL17 also says "If the destination address is in the
169.254/16 prefix (including the 169.254.255.255 broadcast address), the
host SHOULD use its link-local source address, if it has one."
I don't believe that it is the intent of LL17 to specify source selection
policy and that this text should not be proposed here - it is relevant to
LL1.

I propose that the text concerning destination access which addresses the
issue of LL17 be separated from Source selection issues as per LL26 and
changed to:

"If either the source or the destination address of a packet to be sent is
in the 169.254/16 prefix (including the 169.254.255.255 broadcast address),
the host MUST NOT send the packet to any router for forwarding. In order to
send the packet the host MUST ARP for the destination address and then send
the packet directly to its destination on the same link."

Philip