What Is Broadcasting?

Date First Published: 8th June 2022

Topic: Computer Networking

Subtopic: Data Transmission Technologies

Article Type: Computer Terms & Definitions

Difficulty Level: 6/10

Learn more about what broadcasting is in this article.

Broadcasting refers to the process of sending a message to all hosts on a network without knowing their unique IP addresses. It can be thought of as talking to everyone in the same room at once without knowing all of their names, since broadcasting works in a similar way to that. Broadcasting is carried out by networking hardware such as routers and switches, which are responsible for sending data packets to all devices connected to the same network. It is a one-to-all form of communication as one sender transmits a message to all receivers in a network.

Note:

Every network has a preassigned broadcast address. A single packet from one sender is routed to every possible host associated with the broadcast address. The network automatically copies packets as needed to reach all the recipients within the broadcast.

Advantages and Disadvantages Of Broadcasting

• It is a quick method of sending messages to hosts on a network. It does not require hosts to be individually selected or their IP addresses to be known.
• Information can be widely distributed and does not have to be sent multiple times.

• It cannot handle a large number of devices, since the broadcast is limited to the subnet of the broadcast host.
• It does not allow personalisation of messages in accordance with the preferences of the hosts.
• It can be abused to form a type of DoS attack, known as a Smurf Attack. This occurs when an attacker sends large numbers of ICMP messages with the spoofed source IP address of the victim’s computer, causing the victim's computer to be flooded with replies from all the computers.

Limitations

Not all network technologies support broadcasting. For example, X.25 and frame relay do not have broadcast capabilities. Even though IPv4 supports broadcast, the broadcast is limited to the subnet of the broadcast host. Usually, this is small and it is impossible to carry out an internet-wide broadcast. Broadcasting is mostly limited to LAN technologies, such as Ethernet and Token Ring.

IPv6, the more recent and advanced version of the Internet Protocol, does not use broadcasting. Instead, IPv6 uses multicast addressing, which puts a limit on the pool of receivers to those that join a specific multicast receiver group.

Difference Between Broadcasting, Multicasting, and Unicasting

Broadcasting is different from multicasting or unicasting. Multicasting refers to the process of sending messages to a selected number of recipients or hosts at the same time and there is no defined number of them. However, broadcasting sends messages to all hosts on a network without knowing their individual IP addresses rather than a selected number. Unicasting is completely different as it only sends data to a single recipient or host on a network. It has only one sender and recipient and is much simpler than broadcasting or multicasting.