IPv4 Unicast, Broadcast, and Multicast (Free Preview)

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Unicast – A unicast IPv4 address is assigned to a single TCP/IP host. The unicast communication refers to the process of sending a packet from one host to another host (one-to-one communication).


Broadcast – Assigned to all TCP/IP hosts located on the network. This type of communication refers to the process of one host sending a packet to all other hosts in the network (one-to-everyone-on-a-subnet communication).


Multicast – Assigned to one or more TCP/IP hosts located on various subnets on the network. This is the process of sending a packet from one host to a selected group of hosts and the interested hosts may be in different networks (one-to-many communication).


Unicast Communication

  • This is used for normal host-to-host communication.
  • In an IPv4 network, a unicast address assigned to an end device is referred to as the host address.
  • In unicast communication, a TCP/IP host uses it’s IPv4 address as the source IP address and uses the destination hosts IPv4 address as the destination IP address when encapsulating the packet at the network layer.
  • Unicast packets can be routed through an internetwork.


Figure Unicast communication in network /24


Broadcast Communication

  • Broadcast Traffic are received by all hosts on the same subnet as the transmitting host.
  • Every TCP/IP host other than the host that transmitted the broadcast will process the received broadcast packet.
  • This is a single-packet transmitted to everyone on the subnet.



Figure Broadcast communication in network /24


Multicast Communication

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