The correct answer is: C. Ethernet address
An Ethernet address, also known as a MAC address, is a unique identifier assigned to network interfaces for communications on the physical network segment. It is a 12-digit hexadecimal number, written in the form of six pairs of hexadecimal digits separated by colons, for example: 00:11:22:33:44:55.
The first three pairs of digits are assigned by the Institute of Electrical and Electronics Engineers (IEEE) to identify the manufacturer of the network interface card (NIC). The last three pairs of digits are assigned by the manufacturer to identify the specific NIC.
Ethernet addresses are used in the Media Access Control (MAC) sublayer of the Data Link Layer of the Open Systems Interconnection (OSI) model. They are used to identify devices on a network and to control access to the network.
MAC addresses are often used in conjunction with IP addresses to identify devices on a network. For example, when a computer sends a packet of data to another computer on the same network, it will include the destination computer’s MAC address in the packet header. The network router will then use the destination computer’s MAC address to forward the packet to the correct computer.
MAC addresses are also used in some security protocols, such as MAC filtering. MAC filtering allows network administrators to control which devices are allowed to connect to a network by specifying a list of allowed MAC addresses.
Option A is incorrect because a MAC address is not the same as an IP address. An IP address is a 32-bit number that is used to identify devices on a network. MAC addresses are 12-digit hexadecimal numbers that are used to identify devices on a physical network segment.
Option B is incorrect because an IP address is not the same as an Ethernet address. An IP address is a 32-bit number that is used to identify devices on a network. Ethernet addresses are 12-digit hexadecimal numbers that are used to identify devices on a physical network segment.
Option C is the correct answer because an Ethernet address is a unique identifier assigned to network interfaces for communications on the physical network segment.
Option D is incorrect because HTTP is a protocol that is used to transfer data over the World Wide Web. It is not related to MAC addresses.