ip段/数字,如192.168.0.1/24的意思是什么?
 踩踩 作者:Admin 发表日期:2013-10-31 复制链接 收藏 
 首先来了解一下二进制的转换知识:
二进制数转换成十进制数  二进制的1101转化成十进制 
  1101(2)=1*2^0+0*2^1+1*2^2+1*2^3=1+0+4+8=13 
  转化成十进制要从右到左用二进制的每个数去乘以2的相应次方 
  不过次方要从0开始 
  相反 用十进制的13除以2 每除一下将余数就记在旁边 
  最后按余数从下向上排列就可得到1101 
  十进制转二进制: 
  用2辗转相除至结果为1 
  将余数和最后的1从下向上倒序写 就是结果 
  例如302 
  302/2 = 151 余0 
  151/2 = 75 余1 
  75/2 = 37 余1 
  37/2 = 18 余1 
  18/2 = 9 余0 
  9/2 = 4 余1 
  4/2 = 2 余0 
  2/2 = 1 余0 
  1/2 = 0 余1 
  故二进制为100101110 
子网掩码的前缀表示法!  [/pre][pre]11111111 11111111 1111111 00000000  24个1组成    [/pre][pre]转成成十进制等于 255.255.255.0    [/pre][pre]11111111 11111111 1111111 11111100  30个1组成    [/pre][pre]转成成十进制等于 255.255.255.252 [/pre]
我们租用服务器/vps的时候,买多个IP地址,机房总是发一个类似 10.0.0.1/29 或 10.0.0.1/28 或 10.0.0.1/30
 或 10.0.0.1/27 的地址给我们,对于不熟悉网络的人来说,真的莫名其妙。到底有哪些可用的IP? 网关,子网掩码,广播地址是什么? 
为了方便大家,本文章提供了 可用IP查询,ip段/27 /29 /30 网关,子网掩码,广播地址查询 
可用IP查询,IP段对应表
 IP总数子网掩码C段个数/30/29/28/27/26/24/23/22/21/20/19/18/17/16
| 4 | 255.255.255.252 | 1/64 | 
| 8 | 255.255.255.248 | 1/32 | 
| 16 | 255.255.255.240 | 1/16 | 
| 32 | 255.255.255.224 | 1/8 | 
| 64 | 255.255.255.192 | 1/4 | 
| 256 | 255.255.255.0 | 1 | 
| 512 | 255.255.254.0 | 2 | 
| 1024 | 255.255.252.0 | 4 | 
| 2048 | 255.255.248.0 | 8 | 
| 4096 | 255.255.240.0 | 16 | 
| 8192 | 255.255.224.0 | 32 | 
| 16384 | 255.255.192.0 | 64 | 
| 32768 | 255.255.128.0 | 128 | 
| 65536 | 255.255.0.0 | 256 | 
 
ip段/24 /25 /26 /27 /28 /29 /30 
网关,子网掩码,广播地址查询
范例: 要查询204.45.116.184/29,先找到下表的 /29 表格,网关 这一列找到要查询的IP最后一位即.184,然后就可以看到可用IP范围(注:第一个IP是Gateway网关地址)和广播地址了。然后从上面的表找到 子网掩码即可。
| /25 -- 2 Subnets -- 126 Hosts/Subnet 网络地址可用IP范围广播地址
 
| .0 | .1-.126 | .127 |  
| .128 | .129-.254 | .255 |  | /24 --1 Subnets -- 254 Hosts/Subnet 代表一整个C段
 网络地址可用IP范围广播地址
 /30 -- 64 Subnets -- 2 Hosts/Subnet
 网络地址可用IP范围广播地址
 
| .0 | .1-.2 | .3 |  
| .4 | .5-.6 | .7 |  
| .8 | .9-.10 | .11 |  
| .12 | .13-.14 | .15 |  
| .16 | .17-.18 | .19 |  
| .20 | .21-.22 | .23 |  
| .24 | .25-.26 | .27 |  
| .28 | .29-.30 | .31 |  
| .32 | .33-.34 | .35 |  
| .36 | .37-.38 | .39 |  
| .40 | .41-.42 | .43 |  
| .44 | .45-.46 | .47 |  
| .48 | .49-.50 | .51 |  
| .52 | .53-.54 | .55 |  
| .56 | .57-.58 | .59 |  
| .60 | .61-.62 | .63 |  
| .64 | .65-.66 | .67 |  
| .68 | .69-.70 | .71 |  
| .72 | .73-.74 | .75 |  
| .76 | .77-.78 | .79 |  
| .80 | .81-.82 | .83 |  
| .84 | .85-.86 | .87 |  
| .88 | .89-.90 | .91 |  
| .92 | .93-.94 | .95 |  
| .96 | .97-.98 | .99 |  
| .100 | .101-.102 | .103 |  
| .104 | .105-.106 | .107 |  
| .108 | .109-.110 | .111 |  
| .112 | .113-.114 | .115 |  
| .116 | .117-.118 | .119 |  
| .120 | .121-.122 | .123 |  
| .124 | .125-.126 | .127 |  
| .128 | .129-.130 | .131 |  
| .132 | .133-.134 | .135 |  
| .136 | .137-.138 | .139 |  
| .140 | .141-.142 | .143 |  
| .144 | .145-.146 | .147 |  
| .148 | .149-.150 | .151 |  
| .152 | .153-.154 | .155 |  
| .156 | .157-.158 | .159 |  
| .160 | .161-.162 | .163 |  
| .164 | .165-.166 | .167 |  
| .168 | .169-.170 | .171 |  
| .172 | .173-.174 | .175 |  
| .176 | .177-.178 | .179 |  
| .180 | .181-.182 | .183 |  
| .184 | .185-.186 | .187 |  
| .188 | .189-.190 | .191 |  
| .192 | .193-.194 | .195 |  
| .196 | .197-.198 | .199 |  
| .200 | .201-.202 | .203 |  
| .204 | .205-.206 | .207 |  
| .208 | .209-.210 | .211 |  
| .212 | .213-.214 | .215 |  
| .216 | .217-.218 | .219 |  
| .220 | .221-.222 | .223 |  
| .224 | .225-.226 | .227 |  
| .228 | .229-.230 | .231 |  
| .232 | .233-.234 | .235 |  
| .236 | .237-.238 | .239 |  
| .240 | .241-.242 | .243 |  
| .244 | .245-.246 | .247 |  
| .248 | .249-.250 | .251 |  
| .252 | .253-.254 | .255 |  | 
| /26 -- 4 Subnets -- 62 Hosts/Subnet 网络地址可用IP范围广播地址
 
| .0 | .1-.62 | .63 |  
| .64 | .65-.126 | .127 |  
| .128 | .129-.190 | .191 |  
| .192 | .193-.254 | .255 |  | 
| /27 -- 8 Subnets -- 30 Hosts/Subnet 网络地址可用IP范围广播地址
 
| .0 | .1-.30 | .31 |  
| .32 | .33-.62 | .63 |  
| .64 | .65-.94 | .95 |  
| .96 | .97-.126 | .127 |  
| .128 | .129-.158 | .159 |  
| .160 | .161-.190 | .191 |  
| .192 | .193-.222 | .223 |  
| .224 | .225-.254 | .255 |  | 
| /28 -- 16 Subnets -- 14 Hosts/Subnet 网络地址可用IP范围广播地址
 
| .0 | .1-.14 | .15 |  
| .16 | .17-.30 | .31 |  
| .32 | .33-.46 | .47 |  
| .48 | .49-.62 | .63 |  
| .64 | .65-.78 | .79 |  
| .80 | .81-.94 | .95 |  
| .96 | .97-.110 | .111 |  
| .112 | .113-.126 | .127 |  
| .128 | .129-.142 | .143 |  
| .144 | .145-.158 | .159 |  
| .160 | .161-.174 | .175 |  
| .176 | .177-.190 | .191 |  
| .192 | .193-.206 | .207 |  
| .208 | .209-.222 | .223 |  
| .224 | .225-.238 | .239 |  
| .240 | .241-.254 | .255 |  | 
| /29 -- 32 Subnets -- 6 Hosts/Subnet 网络地址可用IP范围广播地址
 
| .0 | .1-.6 | .7 |  
| .8 | .9-.14 | .15 |  
| .16 | .17-.22 | .23 |  
| .24 | .25-.30 | .31 |  
| .32 | .33-.38 | .39 |  
| .40 | .41-.46 | .47 |  
| .48 | .49-.54 | .55 |  
| .56 | .57-.62 | .63 |  
| .64 | .65-.70 | .71 |  
| .72 | .73-.78 | .79 |  
| .80 | .81-.86 | .87 |  
| .88 | .89-.94 | .95 |  
| .96 | .97-.102 | .103 |  
| .104 | .105-.110 | .111 |  
| .112 | .113-.118 | .119 |  
| .120 | .121-.126 | .127 |  
| .128 | .129-.134 | .135 |  
| .136 | .137-.142 | .143 |  
| .144 | .145-.150 | .151 |  
| .152 | .153-.158 | .159 |  
| .160 | .161-.166 | .167 |  
| .168 | .169-.174 | .175 |  
| .176 | .177-.182 | .183 |  
| .184 | .185-.190 | .191 |  
| .192 | .193-.198 | .199 |  
| .200 | .201-.206 | .207 |  
| .208 | .209-.214 | .215 |  
| .216 | .217-.222 | .223 |  
| .224 | .225-.230 | .231 |  
| .232 | .233-.238 | .239 |  
| .240 | .241-.246 | .247 |  
| .248 | .249-.254 | .255 |  |