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I have just started learning from the ICDN1 official Cert book.
I've just covered the concept of Classful Networks.
However when introducing Subnetting, the example has me confused.
It examples an internetwork using 'Five Subnets of Class B network 188.8.131.52', the subnets being 150.9.1.X, 150.9.2.X, etc.
However I'm confused: from what I understood of classful networks, class C IP addresses are defined by the first 3 octets, but to me it seems these are defined by the first 3 octets in a sense, also. I understand that subnetting is trying to sub-divide these networks even more, but how then do you differentiate between a class B subnet of x.x.x , and a class C network?
Obviously I am very new to networking, so apologies for the silly beginner question. I know the answer is something simple, and I'm confused about the concept, but I'm not seeing it.