Comment by teekert

It brings the requirement for a firewall on every endpoint with a unique address. My Phone often has an ipv6 address (found out this holiday wen I couldn't resolve one of sites because of an orphan ipv6 entry nobody noticed), and has little problems. Perhaps there is also "firewalling" on the router and the phone can't even have incoming connections. Not sure. In any case, the phone seems to do fine.