Understanding the /24 after the IP


Sometimes people can find an IP written like 192.168.0.1/24 and they wonder about what that means, here’s a good explanation:
IP addresses are written in decimal notation but are best understood in binary.
Decimal is what we count in and goes from 0 to 9 – hex foes from 0 to 1 (0,1) giving 2 possible numbers for each place holder.
Each segment of an IP address is made up of 8 bits counted in binary from 00000000 = 0 to 11111111=255 counting the 0 that is 256 possible combinations.

In the example of 192.168.0.1/24 – 192.168.0.1 is the IP address and 24 is the Subnet mask written in the number of bits used counting from left to right. In this case
11111111.11111111.11111111.00000000 The first 24 bits are 1 the rest are 0 converting to decimal it reads 255.255.255.0 the purpose of the subnet mast is to tell the computer what part of the IP address is the network and what part is the host (Individual computers on that network) if the example you gave all the computers on your local area network (LAN) would have an address of 192.168.0.xxx (form 1 to 254) (0 and 255 are reserved) so you could connect 254 computers on that network.

One thought on “Understanding the /24 after the IP

  1. Pingback: How to determine IP range given Subnet mask « Brain Knowledge

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