Nice, quick and clean explanation/"new"reminder of subnet versus wildcard masks.
Quoted from Packetlife.net
Many newbie network admins express difficulty with the subnet-versus-wildcard masking paradigm. It is a commonly held belief that a wildcard mask is simply the inverse of a subnet mask, and this is often the case, but not necessarily. Here's a brief rundown explaining the purpose of both mask types. Click here for the rest!