Which is the IP of the computers of a LAN connected to the internet?

Question

I will explain you the configuration of my network..I have many switches and hubs that connect computers in a LAN one another. There's not a Router..The internet connection comes through an Ethernet cable from the outside and goes in a switch..in this way all the computers have access to internet. In such configuration without a router for a remote server outside in the internet which will be the IP of the clients of my LAN. Will I have a public IP for each client ?

Suppose I want that 1 of my clients in the LAN should be a webserver and response to requests from outside in the internet what modifications should I do to my network ?

Answer 1

I would start by figuring out what the IP looks like for each of your computers connected to the network. Is it a routable IP or a non-routable IP? Non-routable IP's can have the following forms:

Class A - 10.0.0.0
Class B - 176.16.0.0
Class C - 192.168.0.0

If the IP of each of your computers doesn't look like that than it's possible each of them actually has a public internet IP. Note that typically in a residental broadband setup, ISP's don't permit pulling multiple IP's for a single account. You might be violating your ISP's TOS if you're doing this unless the service you're subscribing to actually allows this -- eg. part of the agreement.

On the otherhand, if each of your computers actually uses the non-routable LAN IP's it's simply a matter of forwarding the appropriate ports to your webserver behind the router.

Answer 2

The first thing you could do is to visit http://www.whatismyip.com/ which shows you your public IP. (Maybe only the indirect public IP.)

Compare this with the IP of your network card. If they match then you know that each machine gets one public IP. If not some network equipment in the path does NAT and hides many machines behind one public IP.