When a station on an Ethernet network sends a frame to the destination MAC address ff:ff:ff:ff:ff:ff, what kind of Layer 2 transmission is being performed?

Introduction / Context:
Ethernet uses MAC (Media Access Control) addresses to deliver frames at the data link layer. There are different types of MAC addresses: unicast, multicast and broadcast. Each type determines how the frame is treated by devices on the local segment. The special MAC address ff:ff:ff:ff:ff:ff is reserved for broadcast and is important for protocols such as ARP, DHCP and others that need to reach all hosts on a local network.

Given Data / Assumptions:

We are working on an Ethernet or IEEE 802.3 network segment.
The destination MAC address is ff:ff:ff:ff:ff:ff, which in binary is all ones (48 bits set to 1).
We are asked to identify the type of transmission represented by this destination address.

Concept / Approach:
In Ethernet, a unicast address identifies a single NIC, typically using a unique MAC. A multicast address identifies a group of receivers that have joined a certain multicast group. The broadcast address, with all bits set to 1, is treated as "send to everyone" on the local broadcast domain. All hosts on the LAN receive the frame, pass it up to their network stacks and then decide whether to process it based on the upper layer protocol.

Step-by-Step Solution:
Recognize that ff:ff:ff:ff:ff:ff is the all ones MAC address, defined by the Ethernet standard as the broadcast address. When a switch or hub sees a frame with this destination MAC, it forwards the frame out all ports in that VLAN or collision domain, except the one on which it was received. All hosts on that LAN segment receive the frame and pass it up the stack. This behavior is characteristic of a broadcast, not a unicast, multicast or anycast transmission. Therefore, the correct classification is a broadcast transmission.

Verification / Alternative check:
You can confirm this by observing ARP requests in a protocol analyzer such as Wireshark. The ARP request "Who has 192.168.1.10?" is typically sent to the destination MAC ff:ff:ff:ff:ff:ff. All devices on the LAN see the request, but only the device with the matching IP responds. This is a classic example of broadcast behavior at Layer 2.

Why Other Options Are Wrong:
Option a (unicast) would use a specific MAC address assigned to a single NIC, not the all ones address.
Option b (multicast) uses special group addresses that start with a specific bit pattern, not all ones; multicast is directed to a subset of hosts, not all of them.
Option c (anycast) is a Layer 3 concept in IP routing where multiple devices share the same IP address, and routing delivers to the nearest instance; it is not a Layer 2 MAC address concept in classic Ethernet.
Option e (hubcast) is not an official networking term and is not used in IEEE standards.

Common Pitfalls:
Some learners confuse broadcast and multicast, assuming both always reach all hosts. In reality, multicast is intended for a selected group, while broadcast is truly "to everyone" on the broadcast domain. Another pitfall is to think that switches block broadcasts by default; they forward them across all ports in the same VLAN, which is why broadcast storms can be a problem in poorly designed networks.

Final Answer:
A frame sent to ff:ff:ff:ff:ff:ff is a broadcast transmission to all hosts on the local network segment.