digraph G {
    node [ shape=box, fontcolor="#ffffff", color="#40a9e3", style="filled"  ]

    label="The VPN IPv6 IoT Router Box (VIIRB) in action"
    node [ shape=box ]
#    rankdir=LR;

#    subgraph cluster_internet  {
        ipv6internet [ label="The IPv6 Internet" shape=oval ]
        ipv4internet [ label="The IPv4 Internet" shape=oval ]
        ipv6vpn [ label="IPv6VPN.ch\nIPv6 via wireguard" shape=oval ]
#    }

#    subgraph cluster_location {
        viirb [ label="The VIIRB" color="#ee1100" ];
#        subgraph cluster_lan {
            lan [ label="Your LAN" ];
            lanclients [ label="Clients in the lan" ]
#        }
#        subgraph cluster_wifi {
            wificlients [ label="WiFi clients" ]
            wifi [ label="IPv6 only wifi: 'IPv6 everywhere'" shape=oval ]
#        }
#    }

    viirb->ipv4internet [ label="Connected via LAN" ]
    ipv4internet->ipv6vpn [ label="Connected to" ]

    viirb->lan [ label="1. Gets IPv4 via cable" ]
    viirb->ipv6vpn [ label="2. Connect the VPN to IPv6VPN.ch" ]
    ipv6vpn->viirb [ label="3. Routes /48 IPv6 network to VIIRB" ]
    viirb->lan [ label="4. Announce IPv6 availability" ]
    lanclients->lan [ label="5. Assign themselves an IPv6 address" ]
    lanclients->ipv6internet [ label="6. Connect via VIIRB to access" ]

    viirb->wifi [ label="A. Provides IPv6 only WiFi" ]
    wificlients->wifi [ label="B. Assign IPv6 address themselves" ]
    wificlients->ipv6internet [ label="C. Connect via VIIRB to access" ]
    wificlients->ipv4internet [ label="D. Use DNS64/NAT64 to access" ]

    ipv6vpn->ipv6internet [ label="Is connected to" ]

    ipv6internet->{wificlients,lanclients} [
        label="SSH, HTTP, HTTPS\nports are open" ]
}