Help to create IP filter

[Hussein Baghdadi]

Hi all.
I have developed a small web forum and I want now to develope an IP blocking filter (like JR's IP filter and other...) to prevent a specifc user from posting.
but I need some help and tips.
1. getRemoteAddress( ) method returns the (IP) address of the client or last proxy that sent the request.
Ok, if this user is behind a proxy, how can I know his IP (so, I can block him) ?
2. Each time a computer connects to internet, it gets a dynamic IP (from DCHP, I think).
well, I have blocked a user which his IP is : 66.122.6.14 (for example).
when he connects to the internet again, he gets a new IP, how can I block him ?
I need every post here...
Thanks.

[Steven Bell]

Basically you can't unless there is some way to capture the MAC address, which I don't think there is.

[Hussein Baghdadi]

mvnforum application has an IP filter ....
this filter uses a properties file that contains the blocked IP.
Any help from our dear moderators ?

[Ben Souther]

MVNForum is an open source project.
You don't need any help from a moderator.

http://sourceforge.net/projects/mvnforum/

[Hussein Baghdadi]

Thanks.
I know it is an open source, but I want some rancher here that he can explains my previous question to me (like how to know the IP ..)....
And since JR contains a similiar filter, our dear moderators can help me .

[Ben Souther]

If you haven't already, download and install Firefox. Then go get the Live HTTP Headers plugin for it. http://livehttpheaders.mozdev.org/
With it, you can see, in real time, exactly what information the browser is sending to the server. This will include the remoteAddress as well as any app specific cookies.

At the moment, Javaranch isn't using MVNForum. It's still using a cgi solution that is not open source and was not put together by the moderators of this forum. The MVNForum version is in the works.

If Javaranch can shut someone off, even after they change IPs, then it's not using a purely IP based solution. It may be using a combination of IP and the cookies it sets.