Subnetting

Subnetting

A subnet allows the flow of network traffic between hosts to be segregated based on a network configuration. By organizing hosts into logical groups, subnetting can improve network security and performance.

Subnet Masking

Applying a subnet mask to an IP address allows you to identify the network and node parts of the address. The network bits are represented by the 1s in the mask, and the node bits are represented by the 0s. Performing a bitwise logical AND operation between the IP address and the subnet mask results in the Network Address or Number.

For example, using our test IP address and the default Class B subnet mask, we get:

10001100.10110011.11110000.11001000      140.179.240.200   Class B IP Address
11111111.11111111.00000000.00000000      255.255.000.000   Default Class B Subnet Mask
--------------------------------------------------------
10001100.10110011.00000000.00000000      140.179.000.000   Network Address

Default subnet masks:

• Class A - 255.0.0.0 - 11111111.00000000.00000000.00000000
• Class B - 255.255.0.0 - 11111111.11111111.00000000.00000000
• Class C - 255.255.255.0 - 11111111.11111111.11111111.00000000