User's Manual

236 Appendix F IP subnetting
N0115791
192.168.1.0 with mask 255.255.255.128 is the subnet itself, and 192.168.1.127
with mask 255.255.255.128 is the directed broadcast address for the first subnet.
Therefore, the lowest IP address that can be assigned to an actual host for the first
subnet is 192.168.1.1 and the highest is 192.168.1.126. Similarly the host ID
range for the second subnet is 192.168.1.129 to 192.168.1.254.
Example: four subnets
The above example illustrated using a 25-bit subnet mask to divide a class C
address space into two subnets. Similarly to divide a class C address into four
subnets, you need to borrow two host ID bits to give four possible combinations
of 00, 01, 10 and 11. The subnet mask is 26 bits
(11111111.11111111.11111111.11000000) or 255.255.255.192. Each subnet
contains 6 host ID bits, giving 2
6
-2 or 62 hosts for each subnet (all 0s is the subnet
itself, all 1s is the broadcast address on the subnet).
Table 49 Subnet 1
Network number Last octet bit value
IP Address 192.168.1. 0
IP Address (Binary) 11000000.10101000.00000001. 00000000
Subnet Mask (Binary) 11111111.11111111.11111111. 11000000
Subnet Address: 192.168.1.0 Lowest Host ID: 192.168.1.1
Broadcast Address: 192.168.1.63 Highest Host ID: 192.168.1.62
Table 50 Subnet 2
Network number Last octet bit value
IP Address 192.168.1. 64
IP Address (Binary) 11000000.10101000.00000001. 01000000
Subnet Mask (Binary) 11111111.11111111.11111111. 11000000
Subnet Address: 192.168.1.64 Lowest Host ID: 192.168.1.65
Broadcast Address:
192.168.1.127
Highest Host ID: 192.168.1.126