P-2302HW/HWL-P1 Series User’s Guide

 

Table 141 Subnet 1 (continued)

 

 

 

 

 

 

 

 

 

IP/SUBNET MASK

 

NETWORK NUMBER

 

LAST OCTET BIT

 

 

 

VALUE

 

 

 

 

 

 

Subnet Address: 192.168.1.0

 

Lowest Host ID: 192.168.1.1

 

 

 

 

 

 

 

 

 

Broadcast Address:

 

Highest Host ID: 192.168.1.126

 

 

 

192.168.1.127

 

 

 

 

 

Table 142 Subnet 2

 

 

 

 

 

 

 

 

 

 

 

IP/SUBNET MASK

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:

Lowest Host ID: 192.168.1.129

 

 

 

192.168.1.128

 

 

 

 

 

Broadcast Address:

Highest Host ID: 192.168.1.254

 

 

 

192.168.1.255

 

 

 

 

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 27 – 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.

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 (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 zeroes is the subnet itself, all ones is the broadcast address on the subnet).

Table 143 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

 

 

 

Appendix C IP Addresses and Subnetting

305