I know traditionally we didn't count the first and last subnet (all zeroes and all ones). So a subnet mask of 255.255.255.192 would give (2^2)-2, or 2, subnets while a mask of 255.255.255.224 would give (2^3)-2, or 6, subnets.
So, for 192.168.201.0/26 the first subnet would be 192.168.201.64 and the first host would be 192.168.201.65.
I know the reason for this, but it seemed rather silly and very wasteful of a scarce resource.
Now, I'm given to believe that this traditional method is no longer used (RFC1878 describes it as obsolete -Instead 255.255.255.192 would give 2^2, or 4, subnets and 255.255.255.224 would give 2^3, or 8, addresses.
I have no problem with this. My questions are:
. Does anyone know if the latest CCNA exams assume the newer or the older method (ie 2^s or (2^s)-2)? . If the newer method, are there any subnet exercises available on the Internet? All the ones I have found seem to use the old method (and so only allow 2 subnets for the mask 255.255.255.192).