Retrieve "user-name" by assigned IP address of a dial-in user

[christds]

I'm developing a web application for ISPs. The users of this application will be the dial-in users of the ISP. I need to retrieve the "user-name" of the dial-in user by using it's assigned IP (I get it from the HTTP protocol when she/he interacts with my application). Do you know where this information (in most common ISP configurations and networks) is logged/kept? Is it on DHCP server of the ISP router, the AAA server, the syslog server??

Thanks in advance for your help.

Sotiris Christodoulou

[pnedeltc]

Before the IP is assiged, the PPP goes through authentication phase.

It depends who is authenticating the user - Radius, tatacs server, localy, otherwise.

Since your user ALREADY has an IP address assigned, the AUTH is O.K.,

thus you should look what kind of logs, the authentication party keeps.

Best,

Plamen