What is the formula to determine the number of usable addresses in a network?

What is the formula to determine the number of usable addresses in a network?

• A. 2n
• B. 2n + 2
• C. 2n - 2
• D. 2n - 1

Answer: (C)

The formula to determine the number of usable addresses in a network is derived from the total number of addresses available in a given subnet. In any IPv4 subnet, the number of total addresses is calculated using the formula 2 raised to the power of n, where n represents the number of bits available for host addresses. However, when determining the number of usable addresses, two specific addresses must be accounted for and excluded: the network address and the broadcast address. The network address is used to identify the subnet itself and cannot be assigned to a host, while the broadcast address is used for sending data to all hosts within that subnet. Thus, the correct formula for calculating the number of usable addresses is 2n - 2. This takes into account the total addresses provided by 2n and subtracts the two addresses that are not usable, leading to the total number of addresses available for assignment to devices on the network. Therefore, the answer reflects the need for this consideration in practical networking scenarios.

The formula to determine the number of usable addresses in a network is derived from the total number of addresses available in a given subnet. In any IPv4 subnet, the number of total addresses is calculated using the formula 2 raised to the power of n, where n represents the number of bits available for host addresses.

However, when determining the number of usable addresses, two specific addresses must be accounted for and excluded: the network address and the broadcast address. The network address is used to identify the subnet itself and cannot be assigned to a host, while the broadcast address is used for sending data to all hosts within that subnet.

Thus, the correct formula for calculating the number of usable addresses is 2n - 2. This takes into account the total addresses provided by 2n and subtracts the two addresses that are not usable, leading to the total number of addresses available for assignment to devices on the network. Therefore, the answer reflects the need for this consideration in practical networking scenarios.