2024年5月10日发(作者：郑问薇)
子网掩码
255.255.255.255
255.255.255.254
255.255.255.252
255.255.255.248
255.255.255.240
255.255.255.224
255.255.255.192
255.255.255.128
255.255.255.0
255.255.254.0
255.255.252.0
255.255.248.0
255.255.240.0
255.255.224.0
255.255.192.0
255.255.128.0
255.255.0.0
255.254.0.0
255.252.0.0
255.248.0.0
255.240.0.0
255.224.0.0
255.192.0.0
255.128.0.0
255.0.0.0
254.0.0.0
252.0.0.0
248.0.0.0
240.0.0.0
224.0.0.0
192.0.0.0
128.0.0.0
0.0.0.0
掩码位
/32
/31
/30
/29
/28
/27
/26
/25
/24
/23
/22
/21
/20
/19
/18
/17
/16
/15
/14
/13
/12
/11
/10
/9
/8
/7
/6
/5
/4
/3
/2
/1
/0
可用主机数
11
20
42
86
1614
3230
6462
128126
256254
512510
10241022
20482046
40964094
81928190
1638416382
3276832766
6553665534
0
262144262142
524288524286
14
20
402
83886088388606
77214
3355443233554430
6712
4217726
268435456268435454
536870
13741822
247483646
42949672964294967294
总IP数C类网段数量
1/256th
1/128th
1/64th
1/32nd
1/16th
1/8th
1/4th
1 half
1
2
4
8
16
32
64
128
256
512
1024
2048
4096
8192
16384
32768
65536
131072
262144
1048576
2097152
4194304
8388608
16777216
33554432
反掩码掩码位正掩码
255.255.255.255
255.255.255.254
255.255.255.252
255.255.255.248
255.255.255.240
255.255.255.224
255.255.255.192
255.255.255.128
255.255.255.0
255.255.254.0
255.255.252.0
255.255.248.0
255.255.240.0
255.255.224.0
255.255.192.0
255.255.128.0
255.255.0.0
255.254.0.0
255.252.0.0
255.248.0.0
255.240.0.0
255.224.0.0
255.192.0.0
255.128.0.0
255.0.0.0
254.0.0.0
252.0.0.0
248.0.0.0
240.0.0.0
224.0.0.0
192.0.0.0
128.0.0.0
0.0.0.0
0.0.0.032
0.0.0.131
0.0.0.330
0.0.0.729
0.0.0.1528
0.0.0.3127
0.0.0.6326
0.0.0.12725
0.0.0.25524
0.0.1.25523
0.0.3.25522
0.0.7.25521
0.0.15.25520
0.0.31.25519
0.0.63.25518
0.0.127.25517
0.0.255.25516
0.1.255.25515
0.3.255.25514
0.7.255.25513
0.15.255.25512
0.31.255.25511
0.63.255.25510
0.127.255.2559
0.255.255.2558
1.255.255.2557
3.255.255.2556
7.255.255.2555
15.255.255.2554
31.255.255.2553
63.255.255.2552
127.255.255.2551
255.255.255.2550
2024年5月10日发(作者：郑问薇)
子网掩码
255.255.255.255
255.255.255.254
255.255.255.252
255.255.255.248
255.255.255.240
255.255.255.224
255.255.255.192
255.255.255.128
255.255.255.0
255.255.254.0
255.255.252.0
255.255.248.0
255.255.240.0
255.255.224.0
255.255.192.0
255.255.128.0
255.255.0.0
255.254.0.0
255.252.0.0
255.248.0.0
255.240.0.0
255.224.0.0
255.192.0.0
255.128.0.0
255.0.0.0
254.0.0.0
252.0.0.0
248.0.0.0
240.0.0.0
224.0.0.0
192.0.0.0
128.0.0.0
0.0.0.0
掩码位
/32
/31
/30
/29
/28
/27
/26
/25
/24
/23
/22
/21
/20
/19
/18
/17
/16
/15
/14
/13
/12
/11
/10
/9
/8
/7
/6
/5
/4
/3
/2
/1
/0
可用主机数
11
20
42
86
1614
3230
6462
128126
256254
512510
10241022
20482046
40964094
81928190
1638416382
3276832766
6553665534
0
262144262142
524288524286
14
20
402
83886088388606
77214
3355443233554430
6712
4217726
268435456268435454
536870
13741822
247483646
42949672964294967294
总IP数C类网段数量
1/256th
1/128th
1/64th
1/32nd
1/16th
1/8th
1/4th
1 half
1
2
4
8
16
32
64
128
256
512
1024
2048
4096
8192
16384
32768
65536
131072
262144
1048576
2097152
4194304
8388608
16777216
33554432
反掩码掩码位正掩码
255.255.255.255
255.255.255.254
255.255.255.252
255.255.255.248
255.255.255.240
255.255.255.224
255.255.255.192
255.255.255.128
255.255.255.0
255.255.254.0
255.255.252.0
255.255.248.0
255.255.240.0
255.255.224.0
255.255.192.0
255.255.128.0
255.255.0.0
255.254.0.0
255.252.0.0
255.248.0.0
255.240.0.0
255.224.0.0
255.192.0.0
255.128.0.0
255.0.0.0
254.0.0.0
252.0.0.0
248.0.0.0
240.0.0.0
224.0.0.0
192.0.0.0
128.0.0.0
0.0.0.0
0.0.0.032
0.0.0.131
0.0.0.330
0.0.0.729
0.0.0.1528
0.0.0.3127
0.0.0.6326
0.0.0.12725
0.0.0.25524
0.0.1.25523
0.0.3.25522
0.0.7.25521
0.0.15.25520
0.0.31.25519
0.0.63.25518
0.0.127.25517
0.0.255.25516
0.1.255.25515
0.3.255.25514
0.7.255.25513
0.15.255.25512
0.31.255.25511
0.63.255.25510
0.127.255.2559
0.255.255.2558
1.255.255.2557
3.255.255.2556
7.255.255.2555
15.255.255.2554
31.255.255.2553
63.255.255.2552
127.255.255.2551
255.255.255.2550