Which statement about breaking up broadcast domains is accurate?

• A. Routers break up broadcast domains
• B. Switches break up broadcast domains
• C. Broadcast domains are not bounded by routers
• D. A single switch isolates broadcast domains

Answer: (A)

Broadcast domains are bounded by devices that do not forward broadcast frames. Routers operate at layer 3 and do not forward broadcast traffic from one network to another, so each network segment attached to a router’s interface stays in its own broadcast domain. In other words, the router terminates the broadcast domain at each interface, isolating broadcast traffic to that local subnet. Switches, by contrast, will forward broadcasts to all ports within the same VLAN, so they don’t inherently break up broadcast domains unless you divide the network into multiple VLANs; then each VLAN becomes its own broadcast domain due to the VLAN boundaries, not the switch itself. Thus, the statement that aligns with how breaking up broadcast domains works is that routers create those separate domains.