CIDR，子网掩码和可用IP地址快速参考指南（备忘单）

作者

A quick reference Subnet and CIDR guide.

What’s a /28?  How many IPs do I get to use with a /26?  Well, see the table below!
Usable IPs is the Total IPs minus the Network and Broadcast IPs.

CIDRSubnet MaskTotal IPsUsable IPs
/32255.255.255.25511
/31255.255.255.25420
/30255.255.255.25242
/29255.255.255.24886
/28255.255.255.2401614
/27255.255.255.2243230
/26255.255.255.1926462
/25255.255.255.128128126
/24255.255.255.0256254
/23255.255.254.0512510
/22255.255.252.010241022
/21255.255.248.020482046
/20255.255.240.040964094
/19255.255.224.081928190
/18255.255.192.016,38416,382
/17255.255.128.032,76832,766
/16255.255.0.065,53665,534
/15255.254.0.0131,072131,070
/14255.252.0.0262,144262,142
/13255.248.0.0524,288524,286
/12255.240.0.01,048,5761,048,574
/11255.224.0.02,097,1522,097,150
/10255.192.0.04,194,3044,194,302
/9255.128.0.08,388,6088,388,606
/8255.0.0.016,777,21616,777,214
/7254.0.0.033,554,43233,554,430
/6252.0.0.067,108,86467,108,862
/5248.0.0.0134,217,728134,217,726
/4240.0.0.0268,435,456268,435,454
/3224.0.0.0536,870,912536,870,910
/2192.0.0.01,073,741,8241,073,741,822
/1128.0.0.02,147,483,6482,147,483,646
/00.0.0.04,294,967,2964,294,967,294