Retrieving REAL client ip address

[Supra LTD]

Hello,

I was wondering if there is a way using coldfusion with java, to get the real
client ip address even if he/she is behind a proxy or using AOL.

I seen the iRC chat have this, so I was wondering if this was possible. Please
help asap.

-Matt

[Supra LTD]

Anyone?

[Tulsa]

Not sure about getting around proxies, but <cfset newIP = CGI.REMOTE_ADDR> will set newIP equal to the users IP.

[Supra LTD]

I'm interested in a way of getting an IP if a user is behind a proxy or using AOL, using coldfusion with java objects, or with anything for that matter. Thanks anyway.

[SafariTECH]

Web servers only have access to the IP presented to them, so you will always
get the masked IP if it is masked. A web browser simply reflects what the
server tells it to reflect IRC's etc are actually on the client's machine, so
they can get the real IP. The only way MAY be to create an activeX or Java
applet that the user must install on their computer and have it report back to
your server, however in most cases they would be alerted to that, AV solutions
may block it or delete it if not approved and tries to communicate externally,
and many systems will not allow installations if the item is not signed. I'm
not too certain your reasons, but there really is no factual method to get
around masked IPs unless the user wants you to. If you want to ensure unique
identity, try using UUID for the tokens - I have found that regardless of
masking (and even if their IP changes), it causes each machine/user to provide
a unique identifier on our site(s). Again, this can be sidestepped if the user
wants, but it can work if that is your goal.

[Supra LTD]

Hmmm...sounds interesting.

Well, then I am crossing IP out from my list...ok here is why I need this, I
am working on an Active Members/Guests list...and I need to somehow keep the
same session for guests that have cookies disabled.

You may ask why I won't track by IP, reasons for this are proxies, dynamic
ISPs, and AOL which changes Ip address on every page. You would then ask me why
not make it track the first 3 groups of the ip such as 127.0.0.*., but then
again, what if more than 1 person is accessing my site from a network? It would
track the whole network as 1 computer...

Plus, I seen VBulletin, the PHP based message board, do a pretty wild thing.
It uses the same session for a guest, even if he/she Disables Cookies, does NOT
pass it in the URL, and has a dynamic IP, like AOL! I've tried it and they
still track me as 1! So I don't want to buy their software just to get a php
solution of how they do this.

I don't want to be passing the session in the URL because the person can
remove it from the url and create multiple sessions.

Do you have any ideas on how I can accomplish this? Please help. Thanks!

[Tom Jordahl]

Nope. You can't discover the real IP address of a user behind a proxy. That
is one of the points behind having a proxy.

--
Tom Jordahl
Macromedia Server Development

[Unregistered]

No telling how old this is but since it came up first when I was searching for something else.

Create a unique id and include it as a url var on subsequent requests.