ZyXEL g-2000 plusv2 ユーザーガイド
ZyXEL G-2000 Plus v2 User’s Guide
388
last octet bit values 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.
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.
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
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
7
– 2
or 126 hosts for each subnet.
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.
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.
Table 141 Subnet 1
NETWORK NUMBER
LAST OCTET BIT
VALUE
VALUE
IP Address
192.168.1.
0
IP Address (Binary)
11000000.10101000.00000001.
00000000
Subnet Mask
255.255.255.
128
Subnet Mask (Binary)
11111111.11111111.11111111.
10000000
Subnet Address: 192.168.1.0
Lowest Host ID: 192.168.1.1
Broadcast Address:
192.168.1.127
Highest Host ID: 192.168.1.126
Table 142 Subnet 2
NETWORK NUMBER
LAST OCTET BIT VALUE
IP Address
192.168.1.
128
IP Address (Binary)
11000000.10101000.00000001.
10000000
Subnet Mask
255.255.255.
128
Subnet Mask (Binary)
11111111.11111111.11111111.
10000000
Subnet Address:
192.168.1.128
Lowest Host ID: 192.168.1.129
Broadcast Address:
192.168.1.255
Highest Host ID: 192.168.1.254