Understand how to find the valid hosts in a subnet
The best way to do this is to use the equation 256 minus the subnet mask. For example, if you have a 240 mask, you would use 256 240. The result, 16, is your first subnet and your base number, or interval. Keep adding the base number to it self until you reach the value of the subnet mask. The valid hosts are the numbers between the subnets.

Understand how to find a broadcast address in a subnet.
Once you find the valid subnets, you can find the valid hosts, which are the numbers between the subnets minus the broadcast address, which is the last number in the host range. For example, in a 240 mask, the first subnet is 16, and the second subnet is 32. That means the valid hosts are 17 through 30, with 31 being the broadcast address for that subnet.

Key Terms and Concepts

Class A Address
class used to differentiate between a network and node within an IP address, creating very few large networks. The syntax is net.node.node.node.

Class B Address
class used to differentiate between a network and node within an IP address. The syntax is net.net.node.node.

Class C Address
class used to differentiate between a network and node within an IP address, creating many small networks. The syntax is net.net.net.node.

IP address
Network address assigned to a node on a network. Used to send and receive packets or datagrams on an internetwork.

subnetting
The breaking up of an IP network address into smaller networks.

Transmission Control Protocol (TCP)
A connection-oriented protocol specified at the Host-to-Host layer of the DoD model.

Classes of IP addresses

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2. TCP-IP Network-layer protocol Exam Points
3. Network Addressing Exams Points
4. Function of the MAC Address
5. MAC Addresses Exams Point
6. Network Congestion Problem in Ethernet Networks
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