Which of the following is a valid MAC address?

Which of the following is a valid MAC address?

• 193.165.2.1
• 00:D0:59:09:07:51
• 2007:0db8:85a3:0000:0000:8a2e:0470:7457
• 00:D0:59 

EXPLANATION

 A media access control address of a device is a unique identifier assigned to a network interface controller for communications at the data link layer of a network segment. MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet and Wi-Fi. In this context, MAC addresses are used in the medium access control protocol sublayer.

The MAC address is formed in accordance to the rules of the three numbering name spaces, which are managed by the Institute of Electrical and Electronic Engineers (IEEE). The format is six sets of two digits or characters, separated by hyphens. An example of a MAC address is 30-65-EC-6F-C4-58.
Some manufacturers, such as Dell, place a unique identifier in the MAC address, which is called the Organizationally Unique Identifier (OUI), and identifies the manufacturer. The OUIs of some well-known firms are:

• Dell: 00-14-22,
• Cisco: 00-40-96,
• Nortel: 00-04-DC.