IP Adress Swapping

[Squealch]

Do ISP's swap a user's IP addess for every request and if so over what IP address range?

Is there any 'best-practice' regarding this and if ISP's do this can they stop it or limit the range for a single user?

Strange questions? I run a website that uses a combination of session IP address and cookies to determin if they're logged in or not. While it works fine for most there are some site users who get logged out immediately after they've logged in. The reason appears to be because thier IP address has changed between requests.

I've researched the problem and put a patch in place that only checks the first 3 sections of an ip address but some people still have problems... it appears that one persons IP address changed from 198.xxx.xxx.xxx to 196.xxx.xxx.xxx. They both registered to the host saix.net

Any ideas/recommendations would be appreciated.

Thanks...

 

[Squealch]

Telkom has too many users

Incidently, a follow-up to the above...

I approached Telkom SAIX about this who proceeded to explain that this occurs due to load balancing becuase they have soo many users - which I understand, I believe AOL does the same using proxy servers. What I have still not got an answer to is why it's necessary for them to switch users over such wide IP address ranges.

I've informed them that my advice to clients who are experiencing this as a problem is to change service providers (shame for those who have locked themselves in with contacts). Telkom did not seem to have a problem with this...

...still waiting for an answer.

 

[wm0000]

Do ISP's swap a user's IP addess for every request and if so over what IP address range?

Not as far as I know. Even if you are using your ISP's proxy, you should maintain the same client IP until you log out again. You can confirm that here by checking your IP and hostname here or here.

If you use the second link, you will see that for most (probably all?) SAIX clients, you actually have two IP's - the remote address and the forwarded address. (Switch between connection directly to the internet and using your ISP's proxy and you will clearly see the changes). These are different. It all depends how the software on your side manupulates the ENV environmental hash and which one it uses. So long as your software is recording the client address and not the proxy address you should be ok.