Asked by
AL MaMun (4 Golds)
Friday, 18 Dec 2020, 10:51 PM
at (IT Job Preparation
Data Communication and Networking)
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Answer(s):
What exactly is subnetting? Subnetting is taking an IP network and subdividing
it into smaller IP networks called subnetworks, or subnets. Every IP network,
or subnet, is a broadcast domain. A broadcast domain is a collection of devices
that can receive broadcast traffic from each other. Broadcast traffic is
traffic that is delivered to every device on the network. Having a single
broadcast domain, or a "flat network," presents two main problems. 1. In a single large broadcast domain, there is a
large amount of broadcast traffic. Broadcast traffic is very inefficient and
consumes large amounts of resources, such as bandwidth, processor cycles, and
memory. In fact, enough broadcast traffic on a network can cause other
applications, such as email, word processors, and spreadsheets, to be
negatively impacted. 2. When all devices are part of the same broadcast
domain, there are no protocol boundaries between devices, so implementing
security policies is difficult. In other words, there is no easy way to protect
one device from another device without using host-based mechanisms, such as
host-based firewalls, permissions, rights, and anti-virus. These methods serve
a valuable purpose, but they are not very efficient, and they can degrade
performance of the host. The solution to these problems is to break the
single large broadcast domain into several smaller broadcast domains. By doing
this, the number of devices connected to each broadcast domain is smaller. This reduces the amount of broadcast traffic,
improving the performance of all devices on the network. Additionally, a
boundary between devices is created, which greatly improves and simplifies the
implementation of security policies. As an analogy, imagine a single room, and in this
room are five different groups of people; one group in each corner and one
group in the center. Each group of people has a microphone and is discussing a
different topic. If you were a member of one of the groups, picture how
difficult it would be to hear people in your group, concentrate on your topic,
and share confidential information.
Now imagine the single room being separated into
five smaller rooms. Each group now has its own room with a door and can
communicate without competing with the other groups. Each person can hear and
concentrate better and more easily keep confidential information within the
group. The concept of dividing a large room into smaller rooms is the same as
the concept of dividing a large broadcast domain (IP network) into smaller
broadcast domains (subnets). |