I was testing with this just now and this thread confirms my findings
(on 6.2.3)... Too bad ARIN hasn't run out of IPv4 yet, that might have
expedited this as dual stack would become the new 'normal'. This is just
a security risk, plain and simple.
Incredible enough, it looks like it's not possible at this time. There
seem to be new feature requests open as per this thread:
https://forum.fortinet.com/tm.aspx?m=181470 I think it's really bad that
PC's running a dual stack can lead to a compromis...
