When adding a new LAN that must support 4 devices, what is the smallest network mask a network administrator can use?

When adding a new LAN that must support 4 devices, what is the smallest network mask a network administrator can use?

• A. 255.255.255.240
• B. 255.255.255.248
• C. 255.255.255.192
• D. 255.255.255.255

Answer: (B)

To determine the smallest network mask suitable for a new LAN that needs to support 4 devices, it helps to understand how subnet masks work in terms of available host addresses. The subnet mask represented by 255.255.255.248 corresponds to a /29 prefix. This means that there are 3 bits available for host addresses within the last octet of the IP address (the third octet in this case). The formula to calculate the maximum number of usable hosts in a subnet is 2^n - 2, where n is the number of bits available for host addresses. For a /29 subnet, the calculation is as follows: - 2^3 = 8 total addresses. - Subtracting 2 (one address for the network ID and one for the broadcast address), you have 6 usable addresses. This makes a /29 subnet capable of supporting 6 devices, which exceeds the requirement for 4 devices. In contrast, other options provide either too many addresses than required or not enough: - The subnet mask 255.255.255.240 (/28) offers 14 usable addresses, which is more than needed but valid. - The subnet mask 255.255.255.192

To determine the smallest network mask suitable for a new LAN that needs to support 4 devices, it helps to understand how subnet masks work in terms of available host addresses.

The subnet mask represented by 255.255.255.248 corresponds to a /29 prefix. This means that there are 3 bits available for host addresses within the last octet of the IP address (the third octet in this case). The formula to calculate the maximum number of usable hosts in a subnet is 2^n - 2, where n is the number of bits available for host addresses.

For a /29 subnet, the calculation is as follows:

• 2^3 = 8 total addresses.

• Subtracting 2 (one address for the network ID and one for the broadcast address), you have 6 usable addresses.

This makes a /29 subnet capable of supporting 6 devices, which exceeds the requirement for 4 devices.

In contrast, other options provide either too many addresses than required or not enough:

• The subnet mask 255.255.255.240 (/28) offers 14 usable addresses, which is more than needed but valid.

• The subnet mask 255.255.255.192