# Subnetting

• posted

Hello

I am trying to learn subnetting and studied the book. The examples given are to subnet an address where the subnet part of the address is less than 8 bits.

i.e. to subet a class A address with a class B subnet mask or Class B address with a class C subnet mask. I am finding it difficult to understand how to subnet a class A address with a class subnet mask.

Can anyone suggest any online article or ideas please?

• posted

Sorry, the question should be

"How to subnet a Class A address with a Class C mask, or in other words., how to subnet when the subnet part is more than 8 bits.

• posted

Hope this helps. If not, post your specific questions on the forum.

Regards, Steve

• posted

You mean something like:10.0.0.0/24 Well, the subnet portion is the 2nd and

3rd octet. There will be 2^16(bits) - 2 = 655342 subnets and 2^8(bits) - 2 = 254 hosts per subnet.

Here is the math you need for subnetting: To find 2^16, all you have to do is multiply 2^8 (256) x 2^8 (256) = 65536 (easy number to memorize). Also memorize 2^10=1024. If you have 13 bits for the subnet, then multiply 1024 x 2 three times. In our case, if you multiply

1024x2 six times, the result will be 65536!

new guy :)

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