And what are the advantages of creating subnetworks if computers are assigned different IP addresses from the same range and can communicate with each other also with switches?

  • Did any answer help you? if so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer. – Ron Maupin Aug 7 '17 at 21:40

The private address ranges specified by the IETF are typically broken down further into smaller ranges called subnets. A router/layer3 switch is required to route traffic (called packets) between the various subnets.

For example is typically broken down to smaller networks such as, a subnet.


A private network is normally a network in one of the RFC 1918 private address ranges:

A subnet, or network, is explained pretty well in this answer.

Hosts can communicate on the same network, or, with routers, across different networks. Networks are layer-3 concepts, and switches switch at layer-2. You should probably study the OSI Model, but remember that it is just a model, and the real world doesn't always work exactly how the model prescribes.

In most cases, a single network (or subnet if you prefer) is assigned to a a single LAN (or VLAN). This constitutes a layer-2 broadcast domain. That means that every broadcast is sent to, and interrupts, every host. It is also often difficult or impossible to put any controls, like security, QoS, etc. within a single LAN.

Breaking a LAN up into separate networks on separate LANs will ease the problem of broadcasts, and it allows you to install controls at layer-3. It also requires a router to be able to get from one network to another.

  • It confuses me that people use words subnet and network interchangeable. So from what I understand a network is actually the Internet (in most cases) in case the subnet is connected to the internet. Or a bigger network... every subnet that is connected to each other forms a network (or would it be more accurate by this definition THE NETWORK) – yoyo_fun Mar 15 '16 at 21:36
  • An internet is a network of networks. The Internet (capital "I") is the largest internet. Many years ago, we had network classes, and these were the networks, and dividing them into smaller networks created subnets. Since CIDR and VLSM (RFCs in 1995), network classes are obsolete, and subnet and network are really interchangeable. – Ron Maupin Mar 15 '16 at 21:40

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