Alcatel Speed Touch Pro User Manual page 210

11 Configuring IP
Example: network and
subnetwork parts
IP address network
classes
Prefix notation for IP
addresses
210 / 340
For example, an IP address is 172.16.0.2 and the subnet mask is
255.255.255.0.
The binary notation of the IP address equals:
10101100.00010000.00000000.00000010
The dotted quad notation of the subnet mask equals:
11111111.11111111.11111111.00000000
Since all the 1 bits of the subnet mask have network significance,
the network part of the IP address would be:
10101100.00010000.00000000.00000010
AND 11111111.11111111.11111111.00000000
10101100.00010000.00000000
or
172.
The subnet part is the remaining part
or
By splitting up the IP address in a network part and a subnetwork
part, it is possible to divide IP addresses in four classes (In fact
five).
These classes are differentiated by the initial bits of an IP address:
Class Range from ... up to ...
A
0.0.0.0 ... 127.255.255.255
B
128.0.0.0 ... 191.255.255.255
C
192.0.0.0 ... 223.255.255.255
D
224.0.0.0 ... 239.255.255.255
A more up to date representation of subnet masks does not refer
to a subnet mask, but to a prefix length.
The prefix number equals the number of ones in the subnet mask.
For example, the subnet mask 255.255.255.0 could also be
written as the prefix /24.
16. 0.
00000010
3EC 17059 AAAA TCZZA Ed. 02
2.
Network Part Bits
8
16
24
32