Can an intruder spoof MAC addresses to get around MAC address filtering?

Spoofing MAC addresses is a technique that an intruder can use to bypass MAC address filtering, which is commonly implemented on networks as a security measure. Each network interface card (NIC) has a unique MAC address assigned to it. When MAC address filtering is enabled, only devices with allowed MAC addresses can connect to the network.

However, because MAC addresses can be easily changed or "spoofed" through software, an intruder can simply configure their device to use an allowed MAC address. This allows them to gain access to the network by masquerading as an authorized device. Therefore, the answer recognizes the feasibility of this action, making it clear that MAC address filtering alone does not provide robust security against someone determined to bypass it.

In this context, the other options may imply limitations or conditions that do not apply generally. For instance, suggesting that spoofing is only possible with physical access underestimates the capability of remote attackers who can also conduct this type of spoofing from their own devices without needing direct physical presence on-site. Similarly, suggesting that it only occurs if MAC filtering is enabled misunderstands the fundamental aspect of spoofing, which is an independent activity that can occur regardless of filtering status.