- This is information that indicates which part of an IP address is the network part and which part is the host part.
- In binary notation, the “1” part is the network part.
- In binary notation, the “0” is the host part.
What is a subnet mask ?
Information that indicates which part of an IP address is information about “which network” and which part is information about “which computer”
Subnet: A smaller network created by dividing a larger network. Think of it like dividing a company’s network into different departments.
IP Address: This is like an address on a network, such as “198.51.100.2”. It identifies a specific device on the network.
Role of Subnet Mask: The subnet mask defines which part of an IP address indicates the network and which part indicates the host within that network.
- Network Portion: Represented by the “1” bits in the binary form of the subnet mask.
- Host Portion: Represented by the “0” bits in the binary form of the subnet mask.
Format of Subnet Mask: It is presented in the same format as an IP address. For example, “255.255.255.0”. When converted to binary, this becomes “11111111.11111111.11111111.00000000”, where the “1” bits represent the network portion and the “0” bits represent the host portion.
Example: For an IP address of “192.168.0.2” with a subnet mask of “255.255.255.0”:
- IP Address in binary: 11000000.10101000.00000000.00000010
- Subnet Mask in binary: 11111111.11111111.11111111.00000000
In this example, the network portion is “11000000.10101000.00000000” and the host portion is “00000010”.
Summary
When you come across the term “subnet mask”, remember that it refers to the information that indicates which parts of an IP address are used for the network and which parts are used for the host. The subnet mask helps differentiate between the network and host sections of an IP address.