Class A IP segment 0.0.0.0 to 127.255.255.255 Class
B IP segment 128.0.0.0 to 191.255.255.255
Class C IP segment 192.0.0.0 to 223.255.255.255
The default subnet mask assigned by XP is only 255 or 0 for each segment
Class A The default subnet mask is 255.0.0.0 A subnet can accommodate up to 16.77 million computers
. The default subnet mask of class B is 255.255.0.0. A subnet can accommodate up to 60,000 computers
. The default subnet mask of class C is 255.255. 255.0 A subnet can accommodate up to 254 computers.
Subnet mask & IP address = network ID
. If the network ID is the same, it belongs to the same network segment.
Example 192.168.0.n 255.255.255.0 Since the previous ones are the same, n&1 must be equal to 0, so it must belong to the same network segment. network segment.
At the same time, the subnet mask determines how many machines can be connected to a network segment.
For example, the subnet mask is 255.255.255.0 11111111.11111111.11111111.00000000
The computer formula is 2 to the power of m, where we can see how many 0s are behind m, how
to set the machine ip so that the machine belongs to the same network segment; if the subnet mask Code 255.255.252.0 11111111.11111111.11111100.00000000
255-252 = 3.
ip group 2 (right to left) addresses can be 00, 01, 10, 11 respectively; because the remainder of these values and 00 is equal to 0
IP identification method
a complete IP Description contains IP address and subnet mask
There are two specific identifications:
192.168.0.n 255.255.255.0
192.168.0.n/24
/24 represents the first 24 bits in the binary identification method of the subnet mask.
| Total number of IPs |
subnet mask |
C segment number |
|
| /30 |
4 |
255.255.255.252 |
1/64 |
| /29 |
8 |
255.255.255.248 |
1/32 |
| /28 |
16 |
255.255.255.240 |
1/16 |
| /27 |
32 |
255.255.255.224 |
1/8 |
| /26 |
64 |
255.255.255.192 |
1/4 |
| /24 |
256 |
255.255.255.0 |
1 |
| /23 |
512 |
255.255.254.0 |
2 |
| /22 |
1024 |
255.255.252.0 |
4 |
| /21 |
2048 |
255.255.248.0 |
8 |
| /20 |
4096 |
255.255.240.0 |
16 |
| /19 |
8192 |
255.255.224.0 |
32 |
| /18 |
16384 |
255.255.192.0 |
64 |
| /17 |
32768 |
255.255.128.0 |
128 |
| /16 |
65536 |
255.255.0.0 |
256 |
24 --1 Subnets -- 254 Hosts/Subnet
represents an entire C segment
| website address | Available IP Ranges | broadcast address |
|---|---|---|
| .0 | .1-.254 | .255 |
/25 -- 2 Subnets -- 126 Hosts/Subnet
| website address | Available IP Ranges | broadcast address |
|---|---|---|
| .0 | .1-.126 | .127 |
| .128 | .129-.254 | .255 |
26 -- 4 Subnets -- 62 Hosts/Subnet
| website address | Available IP Ranges | broadcast address |
|---|---|---|
| .0 | .1-.62 | .63 |
| .64 | .65-.126 | .127 |
| .128 | .129-.190 | .191 |
| .192 | .193-.254 | .255 |
/27 -- 8 Subnets -- 30 Hosts/Subnet
| website address | Available IP Ranges | broadcast address |
|---|---|---|
| .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
| website address | Available IP Ranges | broadcast address |
|---|---|---|
| .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 |
/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 |