digraph G {
    node [ shape=box ]
    label="Why IPv6 upstream on test devices does not work
    ICMP works as it's on 1 reply
    SSH does not work
    Testdev only receives first syn, not 2nd ack packet
    Notebook receives duplicated syn-ack packets from testdev
    Likely problem: router does not see return packet and drops the packet, no session entry?
    It's an outgoing packet, so this should not be a problem
    Router seems only to send first syn packet from the client
    VERIFIED by disabling ip6tables / flushing rules"

    notebook [ label="Notebook: 2a0a:e5c0:13::a/64" ]
    router  [ label="Router: 2a0a:e5c0:13::42/64" ]
    testdev [ label="Testdev: 2a0a:e5c0:13::zz/64" ]

    vpnserver [ label="VPN server" ]

    vpnserver->testdev [ label="Route for 2a0a:e5c1:VPN::/48" ]

    notebook->router [ label="1. Connect to 2a0a:e5c1:VPN::42\nWith MAC
    of router" ]
    router->vpnserver [ label="2. Forwarding packing for Testdev to
    router" ]
    vpnserver->testdev [ label="3. Forwarding packing for Testdev via
    VPN" ]
    testdev->notebook [ label="4. Reply directly to notebook\n
    testdev has same local network as notebook
    Using a different mac address than the router has" ]


}