I want to summarize a subnet in this article.
Let’s get straight to the point.
What is a subnet
A subnet is a network in a network.
By the way, network is a group of connected computing device more than two.
https://www.cloudflare.com/learning/network-layer/what-is-a-subnet/
About a structure of subnet
Subnet is realized by router and switch etc.
In the following image’s case, separate subnet to 135.70.2.0 and 135.70.3.0.
End User’s devices connect switch.
And then, connect switch to router.
By connecting like this, build a subnet.
https://medium.com/@above_the_firewall/what-are-subnets-and-how-do-they-affect-my-networks-48f5da9805c1
What is the purpose of separation?
Reduce traffic of network
If we make the whole thing into one big network, Broadcasts spread all over the network, resulting in unnecessary traffic.
By dividing the network into subnets, communication can be limited to only the necessary range.
Strengthen security
If we set the firefall and the access control per subnet, apply different security policy per department or per purpose.
If we are invaded, we can limit scope of damage.
Efficient usage of IP address
If we only necessary number of IPs in assign specific, we can manage IP address without waste.
Especially with IPv4, addresses are limited, it’s important.
Ease of management
By dividing network per team or department, easy to understand troubleshooting or structure.
Flexibility of network design
Subnet makes it easier to expand in the future.
For example, new locations can be added without affecting the existing configuration.
