Which device does not forward broadcast or multicast packets by default?

A router is designed to operate at the network layer of the OSI model and primarily facilitates communication between different networks, which is why it does not forward broadcast or multicast packets by default. Broadcast packets are typically confined to a local network segment, as they are intended for all devices on that segment. Since routers connect different networks, they do not propagate these packets to reduce unnecessary traffic and maintain efficient data routing.

In contrast, switches, which operate at the data link layer, can forward broadcast packets across the same local network segment. Load balancers and proxy servers also handle traffic differently, typically managing connections at a higher layer and functioning in scenarios that could involve transmitting multicast or broadcast traffic within their own contexts, but they are not primarily designed to restrain such packets as routers do. Thus, the role of a router in network traffic management highlights why it does not forward these types of packets by default.