What is a Subnet Mask?
A 32-bit number that divides an IP address into network and host portions.
Detailed Explanation
The subnet mask uses binary 1s to represent the network portion and 0s for the host portion. When applied to an IP address using a bitwise AND operation, it reveals the network address. Common masks include 255.255.255.0 (/24) for small networks and 255.255.0.0 (/16) for larger ones. Understanding subnet masks is crucial for proper network configuration and routing.
Examples
- •255.255.255.0 - Allows 254 hosts (/24)
- •255.255.255.128 - Allows 126 hosts (/25)
- •255.255.0.0 - Allows 65,534 hosts (/16)