IP address stuff

[nickwrs]

Hey guys,
I have an application that needs to be able to send out information over the net to users all over.
This is of no concern except that I need to get there ip addresses. I have a web server I could have the client program send there ip to, but I don't know how to find the absolute ip adress of people.

i.e. for a dial up connection it is easy, the ip adress you have registered is yours, but people behind routers and what not have ip adresses like 10.0.0.5 and I need to be able to send them information too!

Pleez help if you can.


NickWRS

[frundatz]

Any IP address that begins with 10. is the Class-A non-routeable block of IP addresses that are only used for private networks. Additionally, anything that begins with 172.(16-31).y.z is the Class-B and 192.168.y.z is the Class-C.

Users coming from any of these addresses typically go through a firewall or proxy server and all appear to have the same external IP address to any servers/clients they connect to.

The short answer to your question (and it looks a lot like the long answer) is that you won't be able to initiate communications with people with such IP addresses. On the other hand, you could have them initiate communications, they would appear to come from their external IP address and their firewall/proxy would handle translating which packet goes where.