ungleich-graphviz/ipv6-naming-with-proxy.dot

digraph G {
    node [ shape=box ]
#    rankdir=LR;

    label="Hostnames for IPv6 only hosts"

    serverv6  [ label="Server (IPv6 only)" ];
    proxy  [ label="Proxy (IPv4+IPv6)" ];

    http [ label="HTTP(s) for\nwww.example.com" ]
    dns [ label="DNS for www.example.com" ]

    dnsv6 [ label="v6.example.com" ]
    dnsv6->serverv6 [ label="Only AAAA entry configured" ]

    clientv4 [ label="IPv4 client" ];
    clientv6 [ label="IPv6 client" ];
    clientdual [ label="Dual Stack client" ];

    dns->proxy [ label="A entry points to proxy" style=dashed ]
    dns->serverv6 [ label="AAAA entry points to the server" style=dashed ]

    {clientv4,clientv6,clientdual}->dns [ label="1. perform a DNS lookup" ]

    clientdual->{proxy,serverv6} [ label="2. Accesses either way" style=dashed ]

    clientv4->proxy [ label="2. Accesses server via proxy" ]
    clientv6->serverv6 [ label="2. Accesses server directly" ]

    proxy->serverv6 [ label="Forwards HTTP/HTTPS requests" ]
    serverv6->http [ label="Serves content for" ]

    {clientv6,clientdual}->serverv6 [ label="3. Access via\nv6.example.com\nAlways directly" ]


}