Subnet

Host NetMask BitMask 254 255.255.255.0 24 128 255.255.255.128 25 64 255.255.255.192 26 32 255.255.255.224 27 16 255.255.255.240 28 8 255.255.255.248 29 4 255.255.255.252 30 2 255.255.255.254 31 1 255.255.255.255 32

 

 

Group 2 (128) Group 4 (64) Group 8 (32) Group 16 (16) Group 32 (8) 0 ~ 127 0 ~ 63 0 ~ 31 0 ~ 15 0 ~ 7 128 ~ 255 64 ~ 127 32 ~ 63 16 ~ 31 8 ~ 15 128 ~ 191 64 ~95 32 ~ 47 16 ~ 23 192 ~ 255 96 ~ 127 48 ~ 63 24 ~ 31 128 ~ 159 64 ~ 79 32 ~ 39 160 ~ 191 80 ~ 95 40 ~ 47 192 ~ 223 96 ~ 111 48 ~ 55 224 ~ 255 112 ~ 127 56 ~ 63 128 ~ 143 64 ~ 71 144 ~ 159 72 ~ 79 160 ~ 175 80 ~ 87 176 ~ 191 88 ~ 95 192 ~ 207 96 ~ 103 208 ~ 223 104 ~ 111 224 ~ 239 112 ~ 119 240 ~ 255 120 ~ 127 128 ~ 135 136 ~ 143 144 ~ 151 152 ~ 159 160 ~ 167 168 ~ 175 176 ~ 183 184 ~ 191 192 ~ 199 200 ~ 207 208 ~ 215 216 ~ 223 224 ~ 231 232 ~ 239 240 ~ 247 248 ~ 255

 

xxx.xxx.xxx.64/27
subnet : 64
host range 65 ~ 94
broadcast : 95

 

출처 : http://blog.naver.com/smingi8080?Redirect=Log&logNo=100024578804