What is a Data Link layer network device that logically separates a network into two segments or collision domains in Ethernet networks?

A bridge operates at the Data Link layer of the OSI model and is used to connect two segments of a network, effectively creating separate collision domains. By doing this, a bridge helps in managing network traffic more efficiently. When it receives a frame, the bridge checks the MAC addresses to determine whether to forward or filter the frame, allowing only necessary traffic to pass between the segments. This segmentation reduces the chances of collisions, as devices on one segment will not impact the other, thereby improving overall network performance.

In contrast, a hub operates at the physical layer and does not segment networks into collision domains; it simply broadcasts data to all connected devices, which can result in more collisions. A switch, while it also operates at the Data Link layer and can create multiple collision domains, is a more advanced device that intelligently directs traffic based on MAC addresses rather than forwarding everything to every port. A router, on the other hand, functions at the Network layer, routing packets between different networks rather than simply segmenting one network.