Quiz Entry - updated: 2026.07.14
What are the three types of IPv4 transmission: unicast, broadcast, and multicast?
Unicast = one-to-one (single host IP), broadcast = one-to-all on the local network (host bits all 1), multicast = one-to-a-group (224.0.0.0–239.255.255.255).
IPv4 Transmission Types:
| Type | Description | Destination Address |
|---|---|---|
| Unicast | One-to-one communication | Specific host IP address |
| Broadcast | One-to-all on local network | All host bits set to 1 (e.g., 192.168.10.255 for /24) |
| Multicast | One-to-many (selected group) | 224.0.0.0 to 239.255.255.255 |
Unicast:
- Most common type of traffic
- Source to single destination
- Example: Web browsing, email
Broadcast:
- Sent to ALL devices on the local network
- Limited broadcast: 255.255.255.255
- Directed broadcast: Network address with all 1s in host portion
- Routers do NOT forward broadcasts by default
Multicast:
- Sent to devices that have "joined" a multicast group
- More efficient than multiple unicasts
- Example: Streaming video, routing protocol updates
Go deeper:
Multicast (Wikipedia) — one-to-group delivery and the 224.0.0.0–239.255.255.255 range.- Broadcasting in networking (Wikipedia) — compares unicast, broadcast, multicast and anycast and the broadcast domain.