Subnetting

Question 1

Describe classful vs classless addressing

Answer 1

Classful addressing uses default network bits to determine network address. Classless addressing uses arbitrary number of network bits to determine network address.

Question 2

Describe a subnet mask

Answer 2

32 bit (4 octets). Network bits = 1. Host bits = 0. Logical and with IP address to get network address.

Question 3

What is CIDR

Answer 3

Classless Internet Domain Routing
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Provides simplified presentation of IP/network bits. Number of network bits after address 192.168.1.63/24 rather than 192.168.1.63 mask 255.255.255.0

Question 4

What is subnetworking?

Answer 4

From a classful address, borrow one of more host bits and use those as network bits. This divides the network into a larger amount of smaller networks

Question 5

What’s the purpose of subnetworking?

Answer 5

Performance; separate broadcast domains, isolate priority traffic (VOIP)
Security; isolate servers from workstations, guest wifi
Ease Troubleshooting, smaller number of directly connected devices to work with

Question 6

Describe the subnetting process

Answer 6

1. Determine the maximum required networks
2. Determine the maximum hosts per network
3. Determine network wide subnet mark (classful)
4. Define block size (often called the magic number)– networks, host ranges, broadcast address