&gt; No, you don&#x27;t. The biggest benefit to using IPv4 as the routing-infrastructure and extra bits (maybe an IP option) to describe the host is that most of the Internet (routers, etc) don&#x27;t need to get upgraded, only hosts. Routers don&#x27;t normally mess with the packets so only the first&#x2F;last wifi&#x2F;switch actually need upgrading. This is a small number of devices (certainly much smaller than all!).<p>That&#x27;s the &quot;BangIP&quot; option discussed in the second half of the article and has all the problems discussed there (e.g. it makes multihoming more-or-less impossible)