保留（私有）地址段

地址分类地址范围 地址段Class A10.0.0.0 - 10.255.255.255Class B172.16.0.0 - 172.31.255.255Class C192.168.0.0 - 192.168.255.255localhost127.0.0.0 - 127.255.255.255zeroconf169.254.0.0 - 169.254.255.255内部路由 (RFC 6598)100.64.0.0 - 100.127.255.255

IP 地址类， IP Address Classes

Class地址段A0.0.0.0 - 127.255.255.255B128.0.0.0 - 191.255.255.255C192.0.0.0 - 223.255.255.255D224.0.0.0 - 239.255.255.255E240.0.0.0 - 255.255.255.255

子网， Subnets

CIDR， Classless Inter Domain Routing 提供了比传统的 IP 地址类更细致的地址划分。CIDR 标记写法是 /XX

CIDR子网掩码地址数通配符/32255.255.255.25510.0.0.0/31255.255.255.25420.0.0.1/30255.255.255.25240.0.0.3/29255.255.255.24880.0.0.7/28255.255.255.240160.0.0.15/27255.255.255.224320.0.0.31/26255.255.255.192640.0.0.63/25255.255.255.1281280.0.0.127/24255.255.255.02560.0.0.255/23255.255.254.05120.0.1.255/22255.255.252.01,0240.0.3.255/21255.255.248.02,0480.0.7.255/20255.255.240.04,0960.0.15.255/19255.255.224.08,1920.0.31.255/18255.255.192.016,3840.0.63.255/17255.255.128.032,7680.0.127.255/16255.255.0.065,5360.0.255.255/15255.254.0.0131,0720.1.255.255/14255.252.0.0262,1440.3.255.255/13255.248.0.0524,2880.7.255.255/12255.240.0.01,048,5760.15.255.255/11255.224.0.02,097,1520.31.255.255/10255.192.0.04,194,3040.63.255.255/9255.128.0.08,388,6080.127.255.255/8255.0.0.016,777,2160.255.255.255/7254.0.0.033,554,4321.255.255.255/6252.0.0.067,108,8643.255.255.255/5248.0.0.0134,217,7287.255.255.255/4240.0.0.0268,435,45615.255.255.255/3224.0.0.0536,870,91231.255.255.255/2192.0.0.01,073,741,82463.255.255.255/1128.0.0.02,147,483,648127.255.255.255/00.0.0.04,294,967,296255.255.255.255

十进制到二进制对应表

十进制子网掩码对应二进制十进制通配符对应二进制2551111 111100000 00002541111 111010000 00012521111 110030000 00112481111 100070000 01112401111 0000150000 11112241110 0000310001 11111921100 0000630011 11111281000 00001270111 111100000 00002551111 1111