[Sleaker]

Well.. that's because with ipv6 you're not technically on a lan everything is exposed by default unless you set it all up differently.

[Dagger2]

Nope, you're on a LAN, and usually the router has a firewall that blocks inbound connections by default. Some OSs (like Windows) also have their own by-default firewalls that block connections from hosts on different networks out of the box.