Well it&#x27;s pretty much the addresses you start using when you&#x27;ve run out of IPv4 addresses everywhere else.<p>A very popular example of this is 100.64&#x2F;10, but one can find little bits here and there. Plenty of providers don&#x27;t just use that range but 1&#x2F;8 is pretty safe to use.<p>There are even posts on networking mailinglists about tests for using the multicast ranges (multicast doesn&#x27;t work* anyway and is now widely considered a &quot;never gonna happen&quot; design). Leave 224.0.0.0&#x2F;24 alone and you can pretty much use the rest of 224.0.0.0&#x2F;4. Also, most of broadcast is fine to use on most networking equipment.<p>* of course, locally within a network it does work for a very small number of multicast streams (certainly doesn&#x27;t work for 2^28 multicast streams as designed, so in ipv6 they upped the number of available multicast channels to 2^120)