Discussion on:

IP subnetting made easy

for me was when ANDing was explained (as an after thought....). I spent about an hour on the internet and subnetting made much more sense. Nowadays I have to work at it harder since I never use it. Thanks for this article, it was a great refresher, and I think the ruler will help tons with VLSM when next I need it. This PDF is going in my permanent collection. Once again, thanks.

i cant understand sub netting i want detail of it can any one give me

its just excellent it solved my all query regarding subnetting

Guys the best on-line subnet calculator. http://www.gwebtools.com/ip-subnet-calculator

im sorry but i think this is more confuseing than what my teacher taught me you only showed class A addresses but it helped a little bit thank you for this article

After reading this i feel very easy to understand the concept

Simple, very nice. Subnets have always been sort of a black magic type deal with me until I read this article.

After 45 days in class and reading I finally have a grasp on subnetting. Thanks.

nt bad

no

its goog...i appreciated the way you expalin it...easy to understand

Thats a very good example Thanks George.

I hadn't even touched subnetting since my MCSE exams back in 2000. Your "IP Subnetting Made Easy" gave me a brief but effective review and helped me tackle a job I'd otherwise have spent 20 instead of 3 hours on.

Thank you!
Bob Lippold

it is very useful to all to know how to do.

Excellent reading and practice material for IT students.
Thanks George

Awesome article! Thank you, I will definitely be using this as a reference in the course of my studies.

How would you answer (and what is the math behind) this question:

Question: How many subnets and hosts per subnet can you get from the network 172.18.0.0 255.255.252.0?

Answer: 64 subnets and 1022 hosts

What is the math behind the following question? Particularly I don;t understand how to calculate number of subnets other than 2^6=64 because 255.0.0.0 is 0 subnet bits and 255.255.252.0 is six subnet bits. Other than a chart how would I know this?

Question: How many subnets and hosts per subnet can you get from the network 172.18.0.0 255.255.252.0?

Answer: 64 subnets and 1022 hosts

what would be the use of getting the SUBNET in our life?

can i get professional help from this team.

IT WAS O.K BUT I STILL THINK THIER IS A SHOTER WAY TO DO THIS SUBNETTING THING REALLY

Lovely

I am currently going to class at ITT Tech. No one ever explained subnetting quite as well as this article has. I have printed this article off and handed it to many people. This is one of those articles that makes the light click on. The trick with the calculator in Windows works wonders! Thanks a ton!

The IP addresses on the lower labels are different from the IP addresses in the green areas. For example, where 10.0.24.0 is in the lower legend, the green area is marked 10.24.0.0. Are they wrong or did I completely misunderstand this graphic?

Thanks for great informational article.

Notable collection!

Thanks,
D
http://www.visitsirsi.com

Hands down the most simple explanation to understand on the subject I have ever seen.

AWESOME Article! I was totally dreading taking certification tests until now. Thank You. I have read the article over a dozen times. The only improvement I could recommend is this. Explain that subnetting is only for Private IP addressing. I had that AHA! moment driving into work 1 morning. Great article!

George

Your article really helped me (I've just been tasked with changing masks to go from 512 to 1024 host addresses) - I especially liked bit about using AND on Windows Calc

Thanks muchly - just the right length and I liked the graphics - very well written

Good on ya!

Simon Trangmar - Adelaide Australia

Thanks, you explained it perfect

Hello George.
Thanks you very much for this useful article,I'm new to subnetting and you have made things much easier to understand. However I been trying to use your system to calculate the number of subnet bits and I am stuck I just can't get the answer. Could you please help. The question is as follows...
How many subnets and hosts per subnet can you get from the network 172.29.0.0 255.255.254.0?
Answer: 128 subnets and 510 hosts

I understand that 255.255.254.0 = (1+8)=9 = 2/9 = 512-2 = 510 hosts
However how do I get the number of subnets?
Any help would be much appreciated.

I realize this is an old post but I'll do my best because this is a good question.
"How many subnets and hosts per subnet can you get from the network 172.29.0.0 255.255.254.0?
Answer: 128 subnets and 510 hosts
I understand that 255.255.254.0 = (1+8)=9 = 2/9 = 512-2 = 510 hosts
However how do I get the number of subnets?"

if a mask of 255.255.254.0 gives you 512 ip's then your subnets are in increments of 2 (think 256x2) in the third octet ie 172.29.0.0-172.29.2.255 then 172.29.3.0-172.29.4.255 ect. each with a mask of 255.255.254.0 you will have 128 of these subnets to cover the 256 possibilities from 0-255 there are many other ways to do the math but I find this one to be the quickest for me.

You do not need to know the number of hosts or ips to find the answer as you can also look at it only from the third octet (256-254=2) which makes the same above true x.x.0.0 - x.x.2.255 ect. and since 256 divided by increments of 2 is 128 you could answer the question if it only asked for maximum number of subnets with that network and mask

"I'll never understand why this isn't explained to students, because it makes mask calculations a lot easier."

The reason this isn't explained is because when it comes test time, you're not going to be allowed to use a calculator. Which is blasphemy, really.

hey everyone-
i'd just like to contribute to the conversation with this video tutorial on IP addressing.

http://www.bosscbt.tv/uncategorized/intro-to-ip-addressing-part-i/

enjoy & good luck!

Hey I am a student and we are starting to learn about this now I was having a bit of trouble understanding it after reading this I know understand it, thanks for the great guide

hi guys iam new, thank to confirm me to join your group...

OK, it makes sense... but something doesn' t add up. When I take and attempt to apply what you just taught to the 10.0.0.0 / 8, I figure that the subnet is 255.255.255.0 and that the IP range has 256 hosts and resides between 10.0.0.0 and 10.0.0.255. So, I figured maybe you made a mistake and it was supposed to be 10.0.0.0 / 24; but EVERYTHING I read agrees with you: 10.0.0.0 / 8 and resides between 10.0.0.0 and 10.255.255.255--- which doesn't work out with what you just taught... so I'm confused again...

oof... looking in the wrong place, I was looking at the subnet length, not the mask length... srry... lol