Windows 7 Forums

Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.

Windows 7: IPv4 subnetting problem.

04 Dec 2013   #1

Windows 7 32 bit
IPv4 subnetting problem.

I'm learning computer networking through online tutorials and courses. I stumbled this problem which I'm not sure if my answer is correct or not. Maybe you guys could check or see if I got the right answer.

Here's the problem:
CBY corporation has 3 offices settled in three different cities. You have one class C network address, which you have divided evenly among the sites. Each site has no more than five managers and six supervisors, however the corporation's growth may require to support for up to 25 users per site.Additionaly CBY corporation plans to expand to two more cities in the next six months. Which subnet mask should you assign to users per site? List the first five available subnet IDs and host ranges.
Here's how I approached the problem:
First thing I did was, I wrote the givens of the problem

1. Corporation: CBY
2. Number of Offices: 3
3. IP add: 1 class of C network address
4. Offices (site) condition: 5 Managers and 6 Supervisors and may require up to 25 users per site.

The way I understood the problem (Please check if my understanding is right), was that the corporation had given the task to build their network using Class C IP addresses. So with the maximum users which is 25 users per site.

So, I formulated an IP which is, having the hosts which is minus 2. I got these IP ranges. - - - - -

I added +1 to the number of maximum users which is 25, and with +1 = 26, because the first and last host addresses is unusable.

Thus my answer correct or not? Need your help.
My System SpecsSystem Spec
04 Dec 2013   #2

Microsoft Community Contributor Award Recipient

Microsoft Windows 7 Home Premium 64-bits 7601 Multiprocessor Free Service Pack 1

since subnets work with bitmasks like, 26 computers is impossible means 11111111.11111111.11111111.11000000

6 zero's so 2^6=64 differents addresses. means 11111111.11111111.11111111.11100000
5 zero's so 2^5 different addresses. so 32 addresses

You have to extract 2 but that you know already. So 30 computers can have an unique tcpipv4 address with subnet mask

Now you created 8 subnets of 32 addresses each. 8*32=256 so easy to remember.
My System SpecsSystem Spec

Thread Tools

Similar help and support threads
Thread Forum
Subnetting on the fly...
Hey Guys! It's been quite some time since I've posted here! I've been quite busy, and finally received my first certification ever, for PCs! I'm A+ Certified now! But to the point! I've posted on a few other tech support sites I visit, and help out on occasionally, but nothing too...
Network & Sharing
IPv6 v IPv4?
I have just been reading about this in a newsletter and I am confused as all heck as to what it means. Does this mean that IPv4 will not exist or exist alongside IPv6 or even can one communicate between a site with IPv6 if you have an IPv4 address and vice versa. I know the tech has got to...
Network & Sharing
IPv6 to replace IPv4?
Hi All I would like to know, since IPv6 has recently been started to roll out worldwide in the attempt to eventually replace IPv4, would it be advisable to change my Adapter settings to use IPv6 instead of IPv4? Or are there still to many devices and servers on the web that only rely on IPv4...
Network & Sharing
Windows 7 - Static IP (IPv4)
Hello everyone. I am trying to establish a static IP address on Windows 7 x64. When I have dynamic, my connection is fine. When I try to set up static IP on an unused address, it connects and then I can load certain web pages, while others get server not found, and some have limited...
Network & Sharing
IPv4 has changed
Hello, I have a big problem, first I was using IPv4 : and everything was allright now I have a big problem my IPv4 has changed to and I can't access the internet (its so slow so slow) now its 2:30 AM here and I am getting 5kbps. How to restore it back what to do ? I am...
Network & Sharing
Wrong IPv4 address
OK, Here is my problem, I just reset my router and for some reason my router keeps assigning my pc the ip of so I cant connec with my pc. The default gateway and the range is -, every other pc and devices get proper ip address can anyone help?
Network & Sharing

Our Sites

Site Links

About Us

Find Us

Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

Designer Media Ltd

All times are GMT -5. The time now is 09:42.

Twitter Facebook Google+

Windows 7 Forums

Seven Forums Android App Seven Forums IOS App