Does anyone know of any good websites to show me how to solve these answers?
I DON"T WANT THE ANSWERS. I just need a good website that can help me figure it out. The book i'm reading doesn't really help me. Or maybe it just isn't detailed enough for me to understand.

Your computer has a IP Address of 172.18.56.17 with a subnet mask of 255.255.248.0. Which of the following IP addresses are on your local subnet.

What is the maximum number of workstations the subnet mask 255.255.240 can support on the local subnet?

You have been assigned the network address 172.32.0.0 to use on your LAN. You need to divide the network into seven subnets. What subnet mask do you use.

You have been assigned the network ID 172.16.5.0 with a subnet mask of 255.255.255.0. What is the maximum number of workstations you can have on the subnet?

PCChuck has a good networking website
EZLan.net is also good

I looked through ezlan and got dizzy. I'll have to look at it again after work. I couldn't find pcchuck.

Here's one of his pages:
http://nitecruzr.blogspot.com/2005/10/irre...visibility.html

FWIW - Networking gives me a headache also!

thanks a lot Usasma!

Realistically the only way to explain how to do sub netting is to answer the questions really. But explain how you got the answer. I will start with a few things that you need to know.
A IP address can't end with 0 or 255. So this means for each class C subnet you can have a total of 254 IP addresses.
Class A subnet is as follows 255.0.0.0
Class B subnet is as follows 255.255.0.0
Class C subnet is as follows 255.255.255.0
Each part of the ip address is broken down into Binary.
So Binary for a Class C Subnet would be
11111111.11111111.11111111.0000000

But I have just found something that will help explain.

http://www.learntosubnet.com/Subnet_Section_helper.htm

It is a very hard thing to get your head arround. Basically either learn and remember how many subnets go with which subnet mask and where the IP addresses run from each subnet or get really good at binary.