Trouble Completely Understanding Subnetting

Hello all,

Sorry for the long post. I'm having a really hard time understanding subnetting. I've watched hours of videos online and read up on the subject in a Networking book I own. I understand most of it but when it comes to certain things like finding the ranges of the network I don't really get it. I have 2 examples of questions from a subnetting worksheet that I cant figure out.

Example 1:

Network Address: 195.223.50.0

# Needed Subnets: 2

These are the questions its asking and how I answered them.

• Address Class: C
• Default Subnet Mask: 255.255.255.0
• Custom Subnet Mask: 255.255.255.128 -- I made the hosts portion of the subnet mask .128 because I borrowed 1 bit since I needed 2 subnets
• Total Subnets: 2
• Total Host Addresses: 128 - I answered 128 because there are 7 bits in the host portion left and 2^7 = 128
• Number of usable addresses: 126
• Number of bits borrowed: 1
• What is the subnet broadcast address for the first subnet: 195.223.50.127
• What is the subnet number for the second subnet: 195.223.50.128

I'm pretty confident in those answers, if there is anything wrong with those please help me understand why. But these next two questions confuse me.

• What is the third subnet range?
• What are the assignable addresses for the third subnet?

So is there even a third subnet? Aren't there only two subnets? With the ranges being 195.223.50.0 - 195.223.50.127 and 195.223.50.128 - 195.223.50.255? Is this like a trick question and there isn't a third subnet?

Example 2:

Network Address: 10.0.0.0 /16

Questions:

Address Class: A

Default Subnet Mask: 255.0.0.0

Custom Subnet Mask: 255.255.0.0 - I answered this because /16 means 16 bits for the subnet mask

Total Number of subnets: 256 - 2^8 = 256, 8 bits more than the default subnet mask

Total Host Addresses: 65,536

Total Usable Hosts: 65,534

Number of bits borrowed: 8

These questions I'm not sure about because I dont know which octet changes for each subnet:

What is the 11th subnet range: I think it would be 10.10.0.0 - 10.10.255.255 but not sure.

What is the subnet number for the 6th subnet: 10.5.0.0???

What is the subnet broadcast address for the 2nd subnet: 10.1.255.255???

What are the assignable addresses for the 9th subnet: 10.9.0.1 - 10.9.255.254???

​

Again, sorry for the long post. If I messed up anywhere please let me know what I did wrong. I've been having a rough time trying to figure this out. I'm really having trouble finding the "Magic Number" and the ranges. Any help would be appreciated, Thanks!