I am still wondering why internet-checking cannot be done in
Realbasic. Every browser can and even freeware such as WeatherDock
do check any connection without a hitch: dial-up, adsl, ethernet --
no problem at all. If we search the archives, we find many
questions about how to check if an internet-connection exists, but
no clever answer at all.
Primarily because the idea of being "connected to the Internet" is an
invalid concept. Internet connectivity is not all or nothing, it
can't be represented by a Boolean.
The Internet is an interconnected set of networks. At any given point
in time, your computer may be able to reach some, all or none of the
other networks.
Even if you determine that your computer won't dial its modem if you
ask for a connection to a particular IP network, there's always the
possibility that one or more devices along the path might need to
establish new connectivity to service your request.
eg The AirPort Base Station has a dial on demand modem. So your
connection request might cause a new dial out connection even if
you're atatched to a LAN and you already have established an IP
address.
Similarly some DSL and Cable modems use a connection oriented PPOE
protocol, meaning that outbound traffic might force a "connection"
which requires a user to enter a password, even if your system has
already established an IP address on your LAN.
Or conversely, even if you determine that your computer has internet
connectivity via some interface, opening a new session to some host
might easily take an alternate path which could easily involve
establishing a new dialup connection. Think of the VPN case where
certain IP addresses are routed to the public internet via your ISP
and other IP addresses are routed to your work network, which also
has a path to the Internet.
In any case, as Aaron already said, this isn't a simple question and
so it isn't possible to give a simple answer.
Regards,
Joe Huber
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