Even if we solved MAC address collision on a single link, you have to
remember that a host can be multi-homed to several interfaces. Whatever
we do to support the survival of TCP connections should also work when
the traffic moves from interface A to interface B, e.g. from 802.11 to
GPRS. In such cases, the two interfaces are likely to belong to
different sites, and are like to use different interface identifiers
(since they indeed are different interfaces). The solution of "just
using 64 bits" will not work there.
-- Christian Huitema
If you define the multi-homed 'site' to be the host then I think it
will.