WG Consensus Action: Accept LL33: rework section 2.2 for reattachment

Action: Accept
Change: Section 2.2.  Claiming a Link-Local Address

FROM:
When a network interface transitions from an inactive to an active
state, the host does not have knowledge of what Link-Local IPv4
addresses may currently be in use on that link, since the network
interface may have been inactive when a conflicting address was claimed.

TO:

When a network interface transitions from an inactive to an active
state, the host does not have knowledge of what Link-Local IPv4
addresses may currently be in use on that link, since the point of
attachment may have changed or the network interface may have been
inactive when a conflicting address was claimed.

===========

FROM:

When an interface transitions from inactive to active, the host not
only doesn't have knowledge of LLv4 addresses in use -- it typically
doesn't even know for sure whether it has connected to an alternative
point of attachment.  It is therefore appropriate to determine what
network the host is connected to (such as via probing for a
default gateway or attempting to obtain a routable address)
rather than merely probing for an IPv4LL conflict, potentially
on a different network than the one on which it was originally allocated.

TO:

When a network interface transitions from an inactive to an active
state, the host does not have knowledge of what Link-Local IPv4
addresses may currently be in use on that link, since the point of
attachment may have changed or the network interface may have been
inactive when a conflicting address was claimed.

=============

FROM:

"Were it immediately to begin using a Link-Local IPv4 address which is
already in use by another host, this would be disruptive to that other
host."

TO:

"Were the host to immediately begin using a Link-Local IPv4
address which is already in use by another host, this would be
disruptive to that other host.  Since it is possible that the
host has changed its point of attachment, a routable address may be
obtainable on the new network, and therefore it cannot be assumed that a
Link-Local IPv4 address is to be preferred."