Ethernet MAC Address Field Sizes | Generated by AI
The question asks about the size of the address fields in an IEEE 802.3 MAC frame.
Correct Answer: C (48 bits)
Explanation:
In IEEE 802.3 (Ethernet) MAC frame structure, both the destination address (DA) and source address (SA) are 48 bits long, which equals 6 bytes.
This 48-bit address is also known as a MAC address or physical address, and it’s typically represented in hexadecimal notation with colons or hyphens, such as: 00:1A:2B:3C:4D:5E
Why 48 bits?
- First 24 bits (3 bytes): Organizationally Unique Identifier (OUI) - identifies the manufacturer
- Last 24 bits (3 bytes): Device-specific identifier assigned by the manufacturer
Why Your Answer (B - 32 bits) Was Incorrect:
32 bits would only be 4 bytes, which is insufficient to uniquely identify devices across different manufacturers and networks. The 48-bit address space is necessary to accommodate the large number of devices in modern networks while maintaining the hierarchical structure needed for efficient network administration.
The 48-bit MAC address has been the standard since Ethernet was first standardized and remains in use today.