In this example we have a small network with some

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In this example, we have a small network with some computers, a printer, and a server. Let's say this network uses the IP protocol. So these devices would have IP addresses that look like this. Host A has 192.168.1.50. Host B has 192.168.1.151, and so on. Each device has an IP address. Now I want to point out that in addition to an IP address, each of these hosts also have a MAC address. Remember, every network interface has a hard-coded physical address. Let's say Host A wants to send data to Host B. In an IP network, communication works in much the same way as we talked about previously. In fact, the same packet as before is even used. Here's our original packet with the data and the header that contains the MAC address. But remember, this network uses logical addresses. It uses IP addresses. So what happens is that the packet is encapsulated in another type of packet called an lP packet, which contains the sending host's IP address, and the receiving host's IP address. Now there's an additional step that needs to happen in order to send this packet. Network devices don't inherently know which IP address belongs to which host. They don't know this host is 192.168.1.150, and this host, 192.168.1.151. ARP 5:27-6:18 See, hardware devices use physical addresses to communicate, not logical addresses. So when we use an IP address, the network needs to associate the IP address with the MAC address in order to send the information. This is done by using the address resolution protocol, or ARP. What ARP does is send out a broadcast to all hosts on the network, asking, in this case, if your IP address is 192.168.1.151, send me your MAC address. Hosts on the network that aren't 151 will simply ignore the message. But the host with this IP address, which is Host B in this case will say, that's me, here's my MAC address. They respond with the MAC address. Host A will then associate this MAC address with this IP address. Know that this is a bit of an oversimplification of the ARP process, but it's essentially how it works. Summary 6:19-6:40 OK, so that's it for this lesson. In this lesson, we looked at network addressing. We looked at both the physical address, the MAC address, and the logical address, in this case the IP address. Remember MAC addresses are burned into the hardware of the network interface and cannot be changed.Logical addresses are software-assigned and are dynamic. They can be changed and assigned as needed. IP Addressing 0:00-0:37 The most commonly used network protocol, and the one you'll be working with the most is TCP/IP.Networks that use TCP/IP, use IP addresses to identify hosts on a network. And there are actually two different versions of IP addresses, IPv4 and IPv6 addresses. IPv4 addresses are the most common.IPv6 are less common but are still used, oftentimes, alongside IPv4 addresses.
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