Uploaded September 2021 | Updated September 2026, 2 weeks ago

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A subnet mask is a number that resembles an IP address. It reveals how many bits in the IP address are used for the network by masking the network portion of the IP address. This video also does a short lesson on subnetting. Subnetting is breaking down a large network into smaller networks or subnets.

Chapters:
0:00 Intro
What is an IP address?: 00:10
Subnet Mask: 01:11
Binary Lesson: 01:31
Network and Host parts of an IP address: 07:26
Purpose of Subnetting: 07:50
Subnetting example: 11:01
Subnet Mask classes: 15:03
CIDR: 16:37