Hey WHTites,

I'm working on a project that crosses several subdomains (and even some domains). I don't want to send the SID through the url for security reasons, and cookies won't cross sub-domains. So I came up with the bright idea of tracking people's sessions via their IP, which I will store in the database, and assign to each SID.

I am just getting ready to start coding this system, but my question for you guys is...

How often do ISP's update their DHCP table, and what is the likehood of someone having their dyamic ip changed in mid session?


Thanks Guys

Err. You are asking the wrong question, the question you should ask is "how often will it occur that two separate users ''have'' the same IP" and the answer will be, often enough to be of concern, especially if you are likely to have users from large ISPs such as AOL.

IP is not the way to do this, session identifiers are, or perhaps 3rd party cookies with a little JS.

What would happen if say in a corporate building.. where all traffic goes out through 1 or 2 IP's, will all those people be logged into the site because they can be identifed using the same IP?

I agree with the person above.

hmmm... some good points guys, thanks much

back to the drawing board :D