Based on Research of Mask
Cao Ji-lei · Computer Knowledge and Technology · 2009
We knew the widespread used TCP/IP agreement is distinguishes the different main engine in Internet using the IP address.If you have carried on the TCP/IP agreement establishment,then you can certainly meet the subnet to cover code (subnetmask) this noun,then you knew what was the subnet covers the code? What does it have to affect? How divides the subnet,how calculates the subnet to cover the code? That enters with us this classroom!