ZyXEL Communications ES-2008 each subnet, Chart 5 Subnet, Chart 6 Subnet, Example: Four Subnets, – 2 or 126 hosts for each subnet

Dimension ES-2008 Ethernet Switch

“borrowing”) determines the number of hosts you can have oneach subnet.Chart 5 Subnet 1

	NETWORK NUMBER				LAST OCTET BIT
					VALUE
IP Address	192.168.1.		0
IP Address (Binary)	11000000.10101000.00000001.				0000000
				0
Subnet Mask	255.255.255.		128
Subnet Mask (Binary)	11111111.11111111.11111111.				0000000
				1
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
	Chart 6 Subnet 2
	NETWORK NUMBER				LAST OCTET BIT
					VALUE
IP Address	192.168.1.		128
IP Address (Binary)	11000000.10101000.00000001.				0000000
				1
Subnet Mask	255.255.255.		128
Subnet Mask (Binary)	11111111.11111111.11111111.				0000000
				1
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

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 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 of 00, 01, 10 and 11. The

IP Subnetting O