Which devices propagate collisions?

• A. Hubs And Repeaters.
• B. Bridges, Switches, And Routers Do Not Propagate Collisions.
• C. All Network Devices.
• D. No Devices Propagate Collisions.

Answer: (A)

Collisions occur only within a single shared collision domain. A hub simply repeats every signal to all its ports, so all devices connected through that hub share one collision domain and any simultaneous transmissions can collide across the entire hub. A repeater acts the same way, amplifying and forwarding signals without isolating any portion of the network, so collisions can propagate through it as well. That’s why hubs and repeaters propagate collisions.

In contrast, bridges and switches, and routers, create separate collision domains. A switch or bridge forwards frames only to the appropriate port, so each port (and thus each connection) becomes its own collision domain. Routers separate collision domains across networks. Because of this isolation, they do not propagate collisions beyond their own port. So the statement that hubs and repeaters propagate collisions is the best description, while the others don’t fit the behavior of modern network devices.