Final answer:
A mesh topology requires every node to be connected to every other node, providing high redundancy with extensive cabling and complexity.
Step-by-step explanation:
The physical topology that requires every node to be attached to every other node on the network is called a mesh topology. In a mesh topology, every device on the network has a dedicated point-to-point link to every other device. Because every device is connected to every other device via a dedicated link, the number of links in a mesh topology can be calculated using the formula n(n - 1) / 2, where n is the number of devices. This topology provides a high level of redundancy because if any single link fails, there is always another path for data transfer. However, it is expensive and complex to implement due to the large number of cables and ports required.