What is a broadcast address?
Why Interviewers Ask This
This question tests conceptual clarity. Interviewers want to hear a precise, confident definition before moving to more complex Networking topics. It also reveals how well you can explain technical ideas to non-experts.
Answer
A broadcast address is a special IP address that sends a packet to all devices on a network simultaneously, rather than to a specific host. Limited broadcast (255.255.255.255) sends to all hosts on the local network segment — not forwarded by routers. Directed broadcast uses the host portion all set to 1s for a specific subnet: for 192.168.1.0/24, the broadcast address is 192.168.1.255. ARP requests and DHCP Discovers use broadcasts. The broadcast address is always the last address in a subnet (cannot be assigned to a host). Modern networks disable directed broadcast forwarding to prevent Smurf attacks (ICMP flood amplified by broadcast). IPv6 does not use broadcasts — it replaces them with multicast and anycast addresses, which are more efficient.
Pro Tip
If you're unsure about a detail, say so honestly and explain your reasoning. Interviewers respect candidates who can think through uncertainty rather than bluffing.