Re: LL70: Use of the term "valid"

Jim Busse said:

"Just to clarify my understanding, If the reachability test described in
DNAv4 is skipped, or fails, then IPv4LL can't have a "valid" address,
simply it will have a "routable" address.  In that event, I may assign an
IPv4LL address additionally on that interface, right?"

This might not be a good idea if it's likely that a routable address will
eventually be assigned, since it will cause excessive address changes.
For example in IEEE 802.11, it could be that the reachability test failed
because of packet loss and a subsequent DHCPDISCOVER would succeed.  Is it
helpful to have an IPv4LL address assigned so as to cause existing
connections to go down?  Not necessarily.

In general, the recommended practice is for the host to only assign an
IPV4LL address when it is "likely" that no routable address will be
assigned.  This could occur for example when 802.11 adhoc or Bluetooth PAN
is in use.