Addressing in TCP/IP Protocols

The TCP/IP protocols are a set of rules and protocols that govern the communication and data transfer over the Internet. These protocols utilize various types of addresses to identify and route data packets between devices. The question asks about the address used on the internet when employing TCP/IP protocols. The correct answer is option 'D', which states that all mentioned addresses are used on the internet for employing TCP/IP protocols.

Explanation:

1. Physical Address and Logical Address:
- Physical addresses, also known as MAC (Media Access Control) addresses, are unique identifiers assigned to network interface cards (NICs) at the hardware level. They are assigned by the manufacturer and are typically expressed as a series of hexadecimal digits.
- Logical addresses, such as IP (Internet Protocol) addresses, are used to identify devices on a network. IP addresses are divided into two types: IPv4 and IPv6. IPv4 addresses consist of four sets of numbers separated by periods, while IPv6 addresses are longer and use hexadecimal format.

2. Port Address:
- Port addresses are used to identify specific applications or services running on a device. They work in conjunction with IP addresses to determine which application should receive incoming data packets. Port numbers range from 0 to 65535 and are divided into three categories: well-known ports (0-1023), registered ports (1024-49151), and dynamic or private ports (49152-65535).

3. Specific Address:
- The term "specific address" is not well-defined in the context of TCP/IP protocols. It could refer to any of the above-mentioned addresses or a more specific address used for a particular purpose or scenario.

Conclusion:
In summary, when employing TCP/IP protocols on the internet, all of the mentioned addresses are used. Physical addresses (MAC addresses) and logical addresses (IP addresses) are used for device identification and routing, while port addresses are used to direct data packets to specific applications or services. The term "specific address" could refer to any of these addresses or a more specific address used for a particular purpose. Therefore, the correct answer is option 'D' - all of the mentioned addresses.