Specifications

Waters Network Systems 2800M/MR User’s Manual Page 20
In this diagram, the subnet mask with 25-bit long, 255.255.255.128, contains 126 members in
the sub-netted network. The length of network prefix equals the number of the bit with 1s in that
subnet mask. With this, you can easily count the number of IP addresses matched. The
following table shows the result.
Prefix Length
No. of IP matched
No. of Addressable IP
/32
1
-
/31
2
-
/30
4
2
/29
8
6
/28
16
14
/27
32
30
/26
64
62
/25
128
126
/2
4
256
254
/23
512
510
/22
1024
1022
/21
2048
2046
/20
4096
4094
/19
8192
8190
/18
16384
16382
/17
32768
32766
/16
65536
65534
Table 4.2
10000000.00000001.00000010.1 0000000
128.1.2.128/25
25 bits
1 0000000
1 1111111
All 0s = 128.1.2.128
All 1s= 128.1.2.255
Subne
Network