Capturing Network Address

[davelyds]

How do I go about capturing a users internally assigned network address? I already capture and use their IP address, but want to also capture their internally assigned network address.

 

Most users on my site log in to use the site. If they have a static IP address we can also set it so that all users from that IP address can access the site without entering a username and password (we use this mostly for colleges, where we want to allow access to everyone at the college, but don't want to provide login information to all the students).

 

I have a new client who wants all of the locations of his business to be able to use the site without logging in, and for us to track which of the 250 locations is using the site.  Their network is set up with several IP addresses at their corporate office, and 250 branch locations, each of which has a fixed network address assigned on their intranet.

 

How do I capture that address?

[trq]

Their network is set up with several IP addresses at their corporate office, and 250 branch locations, each of which has a fixed network address assigned on their intranet.

 

If they are all on the same network then they will come from the public facing gateway's ip address.

 

How do I capture that address?

 

Not possible.

[PFMaBiSmAd]

IF (the big if) they were using a proxy server as their Internet gateway at each locaion and IF (another one) it was supplying the internal IP address using the HTTP_X_FORWARDED_FOR header, then you could get the internal network address out of the http request.