Understanding how data travels
Let’s take a look at this really cool example. This is a great example. We’re going see what happens to data when it travels through the network, from the host on left to the host to the right. Before we can do that, we need to identify the differences between two networks. One network is visible on the left, with an IP address of The other network is visible on the right, with a private IP address of We are connecting two private networks over this router. Each host on these networks has a specific IP address and MAC address.
Every node in a network has an IP and aMAC address. Both hosts have both of these. The host on left has as its MAC address and the host on right has as its IP address and all A’s. We must also understand the router’s IP address andMAC address. MAC addresses are not something we normally think of as routers.
When a computer needs access to another network, the router is known as the default gateway. The computer on the left must communicate with the network on its right. To do this, it will talk to the default gateway.
The router will connect you to other networks such as the internet. Your IP configuration will have one, which is basically your routers. Each router interface can have additional IP addresses and/or MAC addresses. Since the router is specialized in routing traffic between networks, each IP address will have a MAC address for that particular interface. As the traffic moves through, we’ll see how this relates.
Host Makes a Packet
We have now identified that there are two different local area networks. The host on left will send a message to host on right stating that I want to send the data to the host at the right. Let’s see what happens. It will take the data and create an IP packet before it can send it. This IP packet will have the destination address. It already knows the address of the host it wants to send it too is so it adds that to the destination address. It also includes its IP address and the source in the IP packet. The header contains the source address of, and the destination address of Once the header is complete, the packet is created. Data is then stuffed into it. What does it do with this packet? It must create a frame.
Packet Makes a Frame
A packet is a good idea.