Question 1

What is a subnet calculator?

Accepted Answer

A subnet calculator is a tool that helps you calculate network parameters like network address, broadcast address, and usable host range from an IP address and subnet mask or CIDR notation.

Question 2

What is CIDR notation?

Accepted Answer

CIDR (Classless Inter-Domain Routing) notation represents the subnet mask as a number after a slash. For example, /24 means a subnet mask of 255.255.255.0, providing 254 usable host addresses.

Question 3

What is the difference between network address and broadcast address?

Accepted Answer

The network address is the first address in a subnet (used to identify the network itself), while the broadcast address is the last address (used to send data to all hosts in the network).

CIDR	Subnet Mask	Usable Hosts	Use Case
/32	255.255.255.255	1	Single host
/31	255.255.255.254	2	Point-to-point links
/30	255.255.255.252	2	Small WAN links
/29	255.255.255.248	6	Small office
/28	255.255.255.240	14	Small department
/27	255.255.255.224	30	Department
/26	255.255.255.192	62	Workgroup
/25	255.255.255.128	126	Small building
/24	255.255.255.0	254	Standard LAN
/16	255.255.0.0	65,534	Large network
/8	255.0.0.0	16,777,214	Class A network

IP Subnet Calculator

CIDR Quick Reference