Finding All Subnets with Exactly 8 Subnet Bits
The formal process in the earlier section “A Formal Process with Less Than 8 Subnet Bits” identified the interesting octet as the octet whose mask value is neither a 255 nor a 0. If the mask defines exactly 8 subnet bits, you have to use a different logic to identify the interesting octet; otherwise, the same process can be used. In fact, the actual subnet IDs can be a little more intuitive.
Only two cases exist with exactly 8 subnet bits:
A Class A network with mask 255.255.0.0; the entire second octet contains subnet bits.
A Class B network with mask 255.255.255.0; the entire third octet contains subnet bits.
In each case, use the same process as with less than 8 subnet bits, but identify the interesting ...
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