ZyXEL Communications MWR222 - V1.0 Manual page 233

octet. This is usually specified by writing a "/" followed by the number of bits in
the mask after the address.
For example, 192.1.1.0 /25 is equivalent to saying 192.1.1.0 with subnet mask
255.255.255.128.
The following table shows some possible subnet masks using both notations.
Table 83 Alternative Subnet Mask Notation
SUBNET ALTERNATIV
MASK E NOTATION
255.255.255.0 /24
255.255.255.1 /25
28
255.255.255.1 /26
92
255.255.255.2 /27
24
255.255.255.2 /28
40
255.255.255.2 /29
48
255.255.255.2 /30
52
Subnetting
You can use subnetting to divide one network into multiple sub-networks. In the
following example a network administrator creates two sub-networks to isolate a
group of servers from the rest of the company network for security reasons.
In this example, the company network address is 192.168.1.0. The first three
octets of the address (192.168.1) are the network number, and the remaining
octet is the host ID, allowing a maximum of 2
MWR222 User's Guide
LAST OCTET LAST OCTET
(BINARY) (DECIMAL)
0000 0000 0
1000 0000 128
1100 0000 192
1110 0000 224
1111 0000 240
1111 1000 248
1111 1100 252
8
– 2 or 254 possible hosts.
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