Jack put forth on 11/17/2010 11:29 AM: > So, I'm still confused as to why it doesn't like that.
This is because you have not educated yourself as to what Classless Inter Domain Routing notation is. To fully understand this you will be required to convert these DECIMAL notations into BINARY notation. Once you have done so, you will see why 23 significant bits and 15 significant bits don't match the notation you are specifying for those networks. The decimal number after the "/" specifies the number of significant bits in the mask of the BINARY representation of the network address. Until you understand TCP/IP addresses and masking in BINARY form you will never fully understand CIDR notation. See: http://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing Keep in mind that all computers speaking TCP/IP do so in binary format, and your TCP/IP stack is processed internally in binary format. Dotted decimal notation is a convenience for humans to be able to comprehend the addresses and masks. CIDR is an attempt to make this even easier, but to use it correctly, you have to understand a little of the binary basics. -- Stan
