Yes, and there are different definitions of 'support.' Since IPv6 has many deployment options 'support' might be the most basic, regular definition where the ro

Yes, and there are different definitions of 'support.' Since IPv6 has many deployment options 'support' might be the most basic, regular definition where the router tries to manage everything and won't work with the network your ISP uses. Normally IPv6 is added as an afterthought. So it won't support many of the advanced features that the V4 interface does. E.g. its very basic to want to set static IPs -> MAC entries when running DHCP. Of the many routers I've tried that 'support' IPv6 they don't offer these features. V4 will also have features for UPnP and even though most routers are probably using miniupnpd (which has support for IPv6) the chances of it having been setup for the router are slim. It's quite useful because UPnP can dynamically let traffic reach IPv6 global scope addresses in your network (with pin holing.) So without this feature networked software can't run services easily (arguably what was meant to be a key benefit for v6.) You know -- the funny thing is -- V6 was meant to give everyone 'public', 'routable' addresses. But the reality is because its firewalled (both at the router and the OS) coupled with the availability of services to automatically let traffic through -- I'd say its less reachable than IPv4. Those who hope that V6 is going to be the future of P2P are in for a bad surprise.