P-2002 Series User’s Guide

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 26-2 or 62 hosts for each subnet (all 0’s is the subnet itself, all 1’s is the broadcast address on the subnet).

Table 51 Subnet 1

IP/SUBNET MASK

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:

Highest Host ID: 192.168.1.62

 

192.168.1.63

 

 

Table 52 Subnet 2

IP/SUBNET MASK

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

 

 

 

 

Table 53 Subnet 3

IP/SUBNET MASK

NETWORK NUMBER

LAST OCTET BIT

VALUE

 

 

 

 

 

IP Address

192.168.1.

128

 

 

 

IP Address (Binary)

11000000.10101000.00000001.

10000000

 

 

 

Subnet Mask (Binary)

11111111.11111111.11111111.

11000000

 

 

 

Subnet Address:

Lowest Host ID: 192.168.1.129

 

192.168.1.128

 

 

Broadcast Address:

Highest Host ID: 192.168.1.190

 

192.168.1.191

 

 

Appendix C

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