Dictionary · Networking Fundamentals
Broadcast
Delivery · Beginner
Delivery to every interface in one local domain. An IPv4 limited form uses 255.255.255.255, and each subnet also has a directed address for the same purpose.
This kind of message is useful for discovery, but every host must notice it. That is why large flat networks become noisy and why routers separate them.
Example: A host sends an address-resolution request to the Ethernet broadcast hardware address so every local device can hear the question.
Common misconception
- A broadcast does not cross a router under normal settings. It is not a way to reach the whole Internet.