Network Segmentation

Network Segmentation refers to

What is CIDR notation?

From Michael N. "CIDR Block Notation Explained in 2 Minutes Updated Aug 15, 2018 (accessed June 1, 2023)

Classless Inter-Domain Routing (CIDR) is a method for allocating IP addresses and organizing IP routing. According to Wikipedia, it was created to slow the growth of routing tables and the rapid exhaustion of IPv4 addresses.

• What is a CIDR block?

  • A CIDR block refers to how many hosts are available on the network and is identified by a "/". The number after this slash has ((2^(32-n))-2) hosts available [the minus 2 is because the first IP address in the block is considered the network ID, and the last address is the broadcast ID.]

     192.168.142.0/24 has 32-24=8... 2^8 = 256
     256 - 2 = 254
     192.168.142.0/24 has 254 available hosts (192.168.142.0 is the Network ID and 192.168.142.255 is the Broadcast ID for this network.)
    

Setting binary aside and using the decimal system, what is the range of numbers found in an octet?

• The range of numbers found in an octect is from 0-255 (there are 256 numbers [aka 2^8..."eight" or octect] and because we begin counting from "0" instead of "1", we only get to 255.)

  • How many octets are found in an IPv4 address?

    • If you have seen a subnet mask express 255.255.255.0, then you'll get that 3 of the 4 octects are full - with only the last available to be changed. There are 4 octects in an IPv4 address.

  • An IPv6 address?

What Is Network Segmentation and Why It Matters?

In your own words, describe network segmentation.

Network segmentation isn’t important as long as the network is using a well configured firewall. Do you agree?

Why or why not?

What is a screened subnet?

Cameras, ID card scanners, locked doors and biometrics are just a few examples of what type of security?

Videos Classful Subnetting

VLANs and Trunking