Subnet mask, 2 subnet mask – Huawei DR814Q User Manual
Page 101
User Manual
Aolynk DR814Q ADSL2+ Broadband Router
9 Appendix - IP Address and Subnet Mask
96
ields of a host ID can be 0s or 255s as these numbers are reserved for
special use.
9.2 Subnet Mask
z
Not all the f
Note:
A network mask looks like a regular IP address and a subnet mask can tell the division
f the network ID and the host ID: A bit set to 1 means this bit is part of the network ID
o
and a bit set to 0 means this bit is part of the host ID.
Subnet masks are used to define subnets (subnets are smaller segments of a large
one). A subnet number is a number of bits borrowed from the host portion of IP address.
Class C address 192.168.1.1 into two subnets, you need to set
ield 4 is also included. Since this
net
hosts
s in field4 can have four values (00, 01, 10, and 11), so there are four
nets. Each subnet uses the remaining six bits in field 4 for its host IDs, ranging from
For example, to divide a
the subnet mask as follows:
255.255.255.128
It is much more straightforward to define the address in binary notation.
11111111. 11111111. 11111111.10000000
For any Class C address, all the bits in the filed 1 through field 3 are part of the network
ID, but note how the mask specifies that the first bit in f
extra bit has only two values (0 and 1), this means there are two subnets. Each sub
uses the remaining 7 bits in field 4 for its host IDs, which range from 1 to 126
(instead of the usual 0 to 255 for a Class C address).
Similarly, to divide a class C network into four subnets, set the mask as follows:
255.255.255.192 or 11111111. 11111111. 11111111.11000000
The two extra bit
sub
1 to 62.