ZyXEL Communications Prestige 2602HW Series, User Manual

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Prestige 2602HW Series User’s Guide
Appendix C IP Subnetting 393
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.
11 000000) or 255.255.255.192. Each subnet
contains 6 host ID bits, giving 2
6
-2 or 62 hosts for each subnet (all 0’s is the subnet itself, all
1’s is the broadcast address on the subnet).
Table 135 Subnet 1
NETWORK NUMBER
LAST OCTET BIT
VALUE
IP Address 192.168.1. 0
IP Address (Binary) 11000000.10101000.00000001. 00 000000
Subnet Mask (Binary) 11111111.11111111.11111111. 11 000000
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 136 Subnet 2
NETWORK NUMBER
LAST OCTET BIT
VALUE
IP Address 192.168.1. 64
IP Address (Binary) 11000000.10101000.00000001. 01 000000
Subnet Mask (Binary) 11111111.11111111.11111111. 11 000000
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
Table 137 Subnet 3
NETWORK NUMBER
LAST OCTET BIT
VALUE
IP Address 192.168.1. 128
IP Address (Binary) 11000000.10101000.00000001. 10 000000
Subnet Mask (Binary) 11111111.11111111.11111111. 11 000000
Subnet Address:
192.168.1.128
Lowest Host ID: 192.168.1.129
Broadcast Address:
192.168.1.191
Highest Host ID: 192.168.1.190