How to distinguish: unicast address, broadcast address, multicast address

In network communication, the type of IP address determines the way packets are delivered. Based on the number and range of targets, network communication methods can be divided into unicast, broadcast, and multicast.

I. Unicast address
1. IPv4 unicast address

The most common communication method in IPv4 is unicast communication. Each IP address uniquely points to a host, and packets are delivered to the corresponding device according to the target address.

Address range: 1.0.0.0 ~ 223.255.255.255
Common use: Communication between devices in home and enterprise LANs
Examples: 192.168.0.10, 10.1.1.5
2. IPv6 unicast address
IPv6 has a wider variety of unicast addresses, which are suitable for different application scenarios:


2. Broadcast address
1. IPv4 broadcast address
IPv4 provides a broadcast mechanism that can transmit data to all hosts in a certain network segment at once. Broadcast is usually used for network initialization, device discovery and other processes.

Restricted broadcast address: 255.255.255.255 (all devices in the local area network)
Targeted broadcast address: such as 192.168.1.255 (for all devices in a subnet)
2. IPv6 broadcast is cancelled
IPv6 no longer supports the broadcast mechanism for the following reasons:


Broadcasting can easily cause network storms
All hosts will process broadcast packets, which is inefficient
The alternative is multicast communication
3. Multicast address



Multicast in IPv4 uses class D addresses, which are used to send data to a specific group of hosts.

Address range: 224.0.0.0 ~ 239.255.255.255
Example: 224.0.0.1 means "all hosts in the local network"
Protocol support: IGMP (Internet Group Management Protocol) is required to manage the multicast membership of the host
2. IPv6 multicast address
The multicast mechanism in IPv6 is more powerful and has become the main means to replace broadcasting.


(1) Address prefix: FF00::/8

(2) Address structure: FF0S::GroupID (S stands for scope), scopes include local, link local, site local, etc.

(3) Example address:

FF02::1 all nodes
FF02::2 all routers
(4) Protocol support: Use MLD (Multicast Listener Discovery) protocol to manage multicast



5. Overview of Address Types