ZyXEL Communications WAP3205 User Manual page 91

Subnetting Example: Before Subnetting
Fig ure 64
You can "borrow" one of the host ID bits to divide the network 192.168.1.0 into two separate sub-
networks. The subnet mask is now 25 bits (255.255.255.128 or /25).
The "borrowed" host ID bit can have a value of either 0 or 1, allowing two subnets; 192.168.1.0 /25 and
192.168.1.128 /25.
The following figure shows the company network after subnetting. There are now two sub-networks,
and .
B
Subnetting Example: After Subnetting
Fig ure 65
In a 25-bit subnet the host ID has 7 bits, so each sub-network has a maximum of 2
hosts (a host ID of all zeroes is the subnet's address itself, all ones is the subnet's broadcast address).
192.168.1.0 with mask 255.255.255.128 is subnet
broadcast address. Therefore, the lowest IP address that can be assigned to an actual host for subnet
is 192.168.1.1 and the highest is 192.168.1.126.
Appendix A IP Addresses and Subnetting
A
WAP3205 v3 User's Guide
91
itself, and 192.168.1.127 with mask 255.255.255.128 is its
A
7
– 2 or 126 possible
A