Chart H-5 Subnet 1 - ZyXEL Communications Vantage RADIUS 50 User Manual

Vantage RADIUS User's Guide
indicate host ID bits "borrowed" to form network ID bits. The number
of "borrowed" host ID bits determines the number of subnets you can
have. The remaining number of host ID bits (after "borrowing")
determines the number of hosts you can have on each subnet.
IP Address
IP Address (Binary)
Subnet Mask
Subnet Mask (Binary)
Subnet Address: 192.168.1.0
Broadcast Address: 192.168.1.127
IP Address
IP Address (Binary)
Subnet Mask
Subnet Mask (Binary)
Subnet Address: 192.168.1.128
Broadcast Address: 192.168.1.255
The remaining 7 bits determine the number of hosts each subnet can have. Host IDs of all zeros represent
the subnet itself and host IDs of all ones are the broadcast address for that subnet, so the actual number of
hosts available on each subnet in the example above is 2
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
H-4
In the following charts, shaded/bolded last octet bit values

Chart H-5 Subnet 1

NETWORK NUMBER
192.168.1.
11000000.10101000.00000001.
255.255.255.
11111111.11111111.11111111.
Chart H-6 Subnet 2
NETWORK NUMBER
192.168.1.
11000000.10101000.00000001.
255.255.255.
11111111.11111111.11111111.
LAST OCTET BIT VALUE
0
00000000
128
10000000
Lowest Host ID: 192.168.1.1
Highest Host ID: 192.168.1.126
LAST OCTET BIT VALUE
128
10000000
128
10000000
Lowest Host ID: 192.168.1.129
Highest Host ID: 192.168.1.254
7
– 2 or 126 hosts for each subnet.
IP Subnetting