ZyXEL Communications MWR102 User Manual page 96

24-bit mask 11111111
29-bit mask 11111111
.
Network Size
The size of the network number determines the maximum number of possible hosts you can have
on your network. The larger the number of network number bits, the smaller the number of
remaining host ID bits.
An IP address with host IDs of all zeros is the IP address of the network (192.168.1.0 with a 24-
bit subnet mask, for example). An IP address with host IDs of all ones is the broadcast address
for that network (192.168.1.255 with a 24-bit subnet mask, for example).
As these two IP addresses cannot be used for individual hosts, calculate the maximum number of
possible hosts in a network as follows:
Table 28 Maximum Host Numbers
SUBNET MASK
8 bits 255.0.0.0
16 bits 255.255.0.0
24 bits 255.255.255.0
29 bits 255.255.255.248 3 bits
Notation
Since the mask is always a continuous number of ones beginning from the left, followed by a
continuous number of zeros for the remainder of the 32 bit mask, you can simply specify the
number of ones instead of writing the value of each octet. This is usually specified by writing a "/"
followed by the number of bits in the mask after the address.
11111111 11111111
11111111 11111111
HOST ID SIZE
24
24 bits 2 – 2
16
16 bits 2 – 2
8
8 bits 2 – 2
3
2 – 2
00000000 255.255.255.0
11111000 255.255.255.248
MAXIMUM NUMBER OF
HOSTS
16777214
65534
254
6
96