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Understanding Subnetting Class C Network

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Either I’m blind, can’t understand or the chart on page 13 f “Administrator’s Guide to TCP/IP is wrong.

The formula 2^x -2 should produce the following from the chart.

1) 1 subnet bit yields 2^1-2= 2-2= 0
2) 2 subnet bit yields 2^2-2= 4-2= 2
3) 3 subnet bit yields 2^3-2= 8-2= 6
4) 4 subnet bit yields 2^4-2= 16-2= 14
5) 5 subnet bit yields 2^5-2= 32-2= 30
6) 6 subnet bit yields 2^6-2= 64-2= 62
7) 7 subnet bit yields 2^7-2=128-2=126

I do not understand 1) above. Your chart indicates 2 subnets but the formula yields 0.

Am I looking at something wrong?

Topic

Subnetting

In reply to Understanding Subnetting Class C Network

The example:
1 subnet bit yields 2^1-2= 2-2= 0
returns zero because 2 adresses have been removed. These are the netadress(usually the lowest), and the broadcast adress.
A nice and handy scheme can be found at
http://www.ipsec.nu/links/subnetmall.gif
Rgds. //Tom

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