This topic is to discuss the following lesson:
Very Good article for Beginners.
Under Class A subnetting section, the subnet mask should be 255.240.0.0 instead of 255.0.0.0.
Typo I guess.
I just glanced over it but couldn’t find that 18.104.22.168, where do you see it?
networklessons and Rene Molenaar = wonderful
Hello Rene, This is great work that you are doing and even if I find it difficult to grasp the concept, I have a feeling that something is happening to my understanding :). Your examples are clear to a point but when I try using my own values, ie other addresses I get lost rather fast :(.
For instance, I have the following address: 22.214.171.124 and 255.255.255.248. I am required to find out 1. Network address. 2.first and last usable addresses and the broadcast address. I figured out that the first address must be the following: 126.96.36.199 and 188.8.131.52 as the network address since it is the first address and that is reserved for the network.
However I am unable or got stuck trying to figure out the broadcast address since it’s the last address is unclear to me. Please let me know how to deal with this issue. Again, thanks for the good work you are doing for hundreds of newbies like me who’d have it rather rough without your help. George
Let’s walk through this example together, that might help…
First we need to figure out the network address and to do that, we need to take a close look at the subnet mask:
The subnet mask defines how large each subnet is. You can do this in binary but I’ll use decimal since it’s faster. A quick method is to take the number 256 minus the subnet mask. We are looking at the 4th octet so that’s 248:
256 - 248 = 8
We now know that each subnet has 8 addresses. Let’s start counting from 0 to show you how it works:
Subnet #1 184.108.40.206
Subnet #2 220.127.116.11
Subnet #3 18.104.22.168
Subnet #4 22.214.171.124
Subnet #5 126.96.36.199
These are all “steps” of 8 addresses. If you keep counting then you’ll end up at the subnet where you 188.8.131.52 address belongs to:
As you can see, your 184.108.40.206 is a network address. The next subnet starts with 220.127.116.11.
Finding the broadcast address is easy now, it’s the last address in the subnet: 18.104.22.168.
Finding the first and last usable host addresses is also easy now…the first address is 22.214.171.124 and the last one is 126.96.36.199 (one before the broadcast address).
Does this help?
You are doing a good Job. I wanted to ask, in your example you have said 188.8.131.52 is the first address for that block? I thought .104 is the network and the first usable address will start from 105? If you could clarify that for me. Thanks
You are correct, and I have corrected the error. Nice catch.