Which device is known to isolate traffic in an Ethernet network?

A bridge is a device that connects and filters traffic between different segments of an Ethernet network, effectively isolating traffic. It works by inspecting the MAC addresses of incoming packets and determining whether to forward or block them based on the address information. This isolation helps reduce collisions and improves overall network performance, reducing unnecessary traffic on a network segment.

In contrast, a repeater simply amplifies signals to extend the distance over which data can travel without addressing any traffic isolation or filtering. A modem, on the other hand, modulates and demodulates signals for communication over a physical medium, primarily focusing on connecting a network to the internet rather than isolating traffic within a local network. Finally, a router connects different networks together and manages traffic between them, but it does so at a layer higher than the Ethernet layer, primarily dealing with IP addresses instead of MAC addresses, making it less effective in isolating traffic within an Ethernet framework compared to a bridge.