Which Ethernet network allows for backward compatibility with 10 Mbit/s Ethernet?

Fast Ethernet is designed to support backward compatibility with 10 Mbit/s Ethernet, also known as 10BASE-T. This compatibility is achieved by using the same cabling infrastructure, specifically twisted pair cabling, and by allowing devices operating at 10 Mbit/s to still communicate effectively on a network that features Fast Ethernet speeds of 100 Mbit/s. Fast Ethernet typically operates using the 100BASE-TX standard, which can detect and negotiate connection speeds, enabling a 10 Mbit/s device to connect seamlessly to a Fast Ethernet network.

In contrast, while Gigabit Ethernet and 10 Gigabit Ethernet can operate over the same physical media, they do not inherently provide backward compatibility with 10 Mbit/s Ethernet standards without additional support or technology. Therefore, it is Fast Ethernet that stands out as the network type primarily maintaining compatibility with the older 10 Mbit/s Ethernet.