Your right, this is off subject, but...here goes nothing.
Please, anyone, correct me if I'm wrong, but NONE of these "solutions" will
do you any good, because they all work at the network layer on the OSI stack
. That means that you can ping the machine that the client is using, but
there are two issues with this. 1)Generally, you will not be allowed to ping
a machine behind a firewall(because it's generally disallowed by the
firewall and most addresses behind a firewall are NAT'ed <ie. not real>). 2)
Aside from issue #1, another issue is that none of these will solve your
problem beacuse you are pining the machine the user is using to see if it's
still reachable, but this will do nothing for you at the application
layer(7). So let's imagine that you write ping software that performs your
ping and replies TRUE or FALSE depending on the ping success. 99% of the
time it will return true because the machine still exists on a network
somewhere is and reachable by ping.
Your solution MUST deal with the application layer to be truly affective.
Hence the applet reccomended earlier.
John D. McDonald
CipherStream Systems
email: [EMAIL PROTECTED]
web: www.cipherstream.com
-------------------------------------------------------
Secure E-Business Is Our Business
-------------------------------------------------------
----- Original Message -----
From: Pankaj <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, November 18, 1999 9:03 AM
Subject: Re: How to know a brower closed
> Hello,
>
> I know this is way off topic, but i found this in the Java Documentation
> (socketOpt.html) that i downloaded. Takea look and correct me if i am
wrong.
> ------------------------------------------------------------------------
> Fell by the wayside...
>
> Some possible BSD options that are not supported in java:
>
> SO_KEEPALIVE:
> With this option, the OS repeatedly pings the connection's peer to
make
> sure it's still there. The conventional wisdom on
> this is that this functionality is best handled at the application
level.
> The Host Requirements RFC specifies a ping interval
> of 2 hours, which is not practically useful.
>
> MSG_OOB:
> This is really an option one passes to a read() or recv() on a socket
to
> read data marked out-of-band or "urgent" if it
> present, before in-band data. If we include this we should also
include
> an option SO_OOBINLINE (below), but this
> doesn't seem to be needed. The real complication against this is that
> we'd also have to provide a symmetrical way to
> write OOB data, and again this hasn't been requested.
>
> SO_OOBINLINE:
> This option will inline OOB data, making it appear inline like
"normal"
> data. It would work in conjunction with
> MSG_OOB.
>
> RAW/ICMP SOCKETS:
> The main argument in favor of this one seemed to be so people could
write
> "ping" in java. Security nightmare. Must be
> root on UNIX machines.
> ------------------------------------------------------------------------
>
> Now, Does this mean i cannot write a pinging utility in Pure Java..? What
do
> they mean by "Security Nightmare. Must be root
> on UNIX machines." Does it have to do anything with "Ping of death."
problem?
> Please clarify anybody..!
>
> Thanx,
> Pankaj
>
>
> ____________________________________________________________________
> Get free email and a permanent address at http://www.netaddress.com/?N=1
>
>
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