A brief introduction on IP allocation:

If you want to apply the IP address from CNNIC, you must become the member of CNNIC first. Moreover, what you should pay attention to is that CNNIC only accept the request of IP addresses in large quantity. In concrete term, it is needed to make full and effective use of the 16 addresses belonging to class C (namely one /20 address section) within one year. Therefore, if your quantity demanded on IP is small, we suggest you to request from some ISPs near you. As for the transformation for various kinds of addresses, you can use the following "calculator for simple address transformation" to calculate.