A network administrator is adding a new LAN to a branch office. The new LAN must support 4 connected devices. What is the smallest network mask that the network administrator can use for the new network?
- 255.255.255.248
- 255.255.255.0
- 255.255.255.128
- 255.255.255.192
Explanation: To support a LAN with 4 connected devices, the network administrator must select a subnet mask that provides a sufficient number of usable host addresses while minimizing wasted address space. The number of usable hosts is calculated using the formula 2n−2, where n represents the number of host bits remaining in the mask. A subnet mask of 255.255.255.248 (which corresponds to a /29 prefix) leaves 3 bits for the host portion, providing 6 usable host addresses. This is the most efficient (smallest) mask among the choices because it satisfies the requirement for 4 devices while leaving fewer unused addresses compared to 255.255.255.192 (/26), 255.255.255.128 (/25), or 255.255.255.0 (/24), which provide 62, 126, and 254 usable addresses respectively.
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