Discuss, How communication over the internet is done using TCP/IP second layer’sMAC addresses and the third layer’s IP addresses.

The communication over the internet is done using a combination of both MAC addresses (Media Access Control) and IP addresses (Internet Protocol). These two are part of the TCP/IP model which stands for Transmission Control Protocol/Internet Protocol.

1. MAC Addresses: MAC addresses are unique identifiers assigned to network interfaces for communications at the data link layer of a network segment. They are used as a network address for most IEEE 802 network technologies, including Ethernet and Wi-Fi. In simple terms, a MAC address can be used to uniquely identify your device on a network.

2. IP Addresses: An IP address, on the other hand, is a unique identifier for a device on a TCP/IP network. Networks using TCP/IP route messages based on the IP address of the destination. The role of the IP address is to identify the host or network interface that provides the location of the host in the network and the identification of the network itself.

Here's how they work together:

Step 1: When a device needs to communicate with another device over the internet, it first needs to know the IP address of the other device. This can be done through a process called DNS resolution.

Step 2: Once the IP address is known, the device will then check if the other device is on the same network or a different one. If it's on the same network, it will use the MAC address to deliver the data. If it's on a different network, it will send the data to the router.

Step 3: The router, which knows the IP addresses of all devices on its network, will then forward the data to the appropriate device using its MAC address.

Step 4: The receiving device will then send an acknowledgment back to the sending device, again using IP and MAC addresses, to confirm that it has received the data.

So, in summary, MAC addresses are used for communication within a network, while IP addresses are used for communication between networks. Both are essential for ensuring data gets from its source to its destination correctly.