forum.vdsworld.com

Serge · Posted: Wed Apr 17, 2002 11:42 am Post subject:

Can someone write such a dll - please!

Serge

Tommy · Posted: Wed Apr 17, 2002 1:47 pm Post subject:

It isn't possible to determine an internet connection through any DLL in
the way you want it. As you mentioned it's possible that a firewall is
blocking certain requests, so you should first think about what you
consider being an internet connection, depending on the kind of
application you need. If you need to know if there's an internet
connection for accessing web pages, you should probably try to connect
to such a server through HTTP as Moke illustrated. If you need to know
whether it's possible to connect to any and all ports on the internet, a ping
should probably do. Some special internet connections might only allow
SMTP and POP3 access while blocking all other connection kind, so would
you consider that being an internet connection too?

The RAS DLL or some of the other methods will only work for modem
connections, so that's probably not what you want.

Tommy

moke · Contributor Joined: 02 Jan 2002 Posts: 162

I agree with Tommy a computer cannot tell the difference between a TCP/IC network connetion an internet conection. It simply sees a network connection. You would need to test each port for each application HTTP, SMTP, FTP etc. to determine whether or not it is accessable through the network connection. They must be tested through an external reference point also since the protocols could run internally but be blocked by the firewall or by using IP port blocking at the router. You need to test for what your application needs are.

moke

Mac · Posted: Wed Apr 17, 2002 10:12 pm Post subject:

I use the VDSIPP.DLL to periodically check my email,
but I had to give the program internet access thru Zone
Alarm. And if I make changes to the program and re-compile
it, Zone Alarm prompts for access again (apparently ZA
does a file check). It also does this with my program that
uses the DOS PING command.

My point is this: a firewall on a user's computer probably
isn't going to allow your program to ping, access the internet
by http, or anything else without the users permission...

Cheers, Mac Smile

Serge · Posted: Thu Apr 18, 2002 11:04 am Post subject:

Thanks for all your comments and thoughts.

I used IPCONFIG at work and found that it does return an IP from the network even if not connected to the net Sad

and hence can't use it to determine access to the net.

Version 5 of VDS apparently will have some Internet support, perhaps it will have what i need.

Thanks again all for your help,

Serge

marty · Professional Member Joined: 10 May 2001 Posts: 789

Did you try my demo that I posted ?

I know it`s not a DLL but it works ok for me.

Wink

Serge · Posted: Thu Apr 18, 2002 11:44 am Post subject:

No because i thought that it worked like the dll mentioned earlier in this post Embarassed

I'll take it to work tomorrow and see if it works for a computer that has a permanent connection to the net through the network.

The problem is that i need to be able to test if a computer is connected to the net in less than 1 sec, whether the computer is networked or not - does your demo do that? Like i said, i'll test it tomorrow.

Thanks for suggesting it again,

Serge

mrfloppy · Newbie Joined: 17 Apr 2002 Posts: 1 Location: england

Here something long time ago i found in Win9/x registry
when dialup connects to inet it make registry changes in hex 00 > 01
ndetect.exe from icq use this long time ago to check if comp was connected to net, but i think icq change the process to win system dll files
:/

--- OFFLINE ---

[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\RemoteAccess]
"Version"="1.2c"
"NoLogon"=hex:00,00,00,00
"Remote Connection"=hex:00,00,00,00

--- ONLINE ---

[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\RemoteAccess]
"Version"="1.2c"
"NoLogon"=hex:01,00,00,00
"Remote Connection"=hex:01,00,00,00

Dr. Dread · Posted: Fri Apr 19, 2002 1:25 am Post subject:

This is turning into quite an interesting thread!

Well, anyway I had a go at it using a couple of PGWARE's DLLs (vdsonline + vdsipp). This proggie
checks the local IP first - if there's only the localhost address 127.0.0.1 then the computer is
offline. If the computer owns another IP then the program makes a ping to a host on the Internet
to try to find out whether the computer is really hooked up to the Net or just on an Intranet etc.
(Use a reliable, fast host). It is not necessary to save any ping output to disk or evaluate it very
much because if the ping returns 'Unknown host' for a well-known host then the computer is most likely
off-line.

Still some caveats: A firewall may block the ping, a proxy may screw things up etc.

Greetz
Dr. Dread

SnarlingSheep · Posted: Fri Apr 19, 2002 3:30 am Post subject:

What about mrfloppy's idea? It works for me on Win 98 with dial-up..would it work elsewhere?
You might also let the user specify whether they have dial-up or a dedicated connection. That way you pretty much don't have to check whether they are online or not if they are dedicated.

Dr. Dread · Posted: Fri Apr 19, 2002 6:29 am Post subject:

Mac · Posted: Fri Apr 19, 2002 7:55 am Post subject:

_____________________________________________________________
Just curious... Has anyone tried the @match() WINLIST
example I posted on an OS other than Windows 95?

It picks up the dialup "Connected to..." window even when
it's only in the sys tray (the two little computers icon).

Also, do cable modems etc. have a similiar window (or some
other indicator for the user) when connected?

Cheers, Mac Smile

Dr. Dread · Posted: Fri Apr 19, 2002 8:12 am Post subject:

marty · Professional Member Joined: 10 May 2001 Posts: 789

Dr. Dread · Posted: Fri Apr 19, 2002 12:57 pm Post subject: