How different rages of ip send data to each other?

Answer 1

Short and simple answer is: routers

A little more detail. A router has a routing table. That table tells it about the networks that are connected to it, and where to send IP packets based on their addresses.

So for example, lets make a simple network:

Subnet A: 10.0.0.0/24

Host A: 10.0.0.2

Subnet B: 10.0.1.0/24

Host B: 10.0.1.2

Router

Interface A: 10.0.0.1

Interface B: 10.0.1.1

Interface C: 10.0.2.1 * default route

So, if you are host A, and you want to send data to host B (on a different subnet) you would have to send your data to Interface A on the router. It would see that you are trying to send data to a different subnet then the one you are on, and it would look in its routing table to see if it knows anything about the subnet 10.0.1.0/24.

Since the router is connected to 10.0.1.0/24 on interface B, the router would send the packet out interface B, and it would end up at host B through the magic of switching.

Now, if we needed to send data to say... Google.com (66.102.7.99) the router would see that address, and not know where to send it, since none of its interfaces are connected to that subnet. The router would then send this packet out its default route, which would lead to a router that had more information on other networks it is connected to. This would continue until eventually it would reach a router that had some idea where the 66.102.7 network is, and the packet would eventually end up at google. I say eventually, and it may take several hops to get to google, but the whole process (from your computer to google -- or wherever) normally is done in under 250 milliseconds. (My packets get to google in about 65 milliseconds).