The subnet mask 255.255.255.255 (also known as a /32 mask) defines a network that contains only a single host address. In this configuration, the device at 192.168.0.74 considers itself to be the only member of its local network. Consequently, it cannot communicate with any other IP address, including the default gateway at 192.168.0.1. To access the internet, the device must be able to send traffic to its default gateway. Since the incorrect subnet mask places the gateway outside the device's local network, all external communication fails.

A. The ipconfig command displays the configured IP settings; it does not provide the operational status of the default gateway device.

B. The IP address 192.168.0.74 is a standard private IP address. An APIPA address would be in the 169.254.0.0 to 169.254.255.255 range.

C. The IP address and default gateway are on the same intended logical subnet (192.168.0.x). The incorrect subnet mask is the root cause of the communication failure.

1. Microsoft Corporation. (2023). TCP/IP fundamentals for Windows. Microsoft Learn. In the "Subnet masks" section

it is explained that the subnet mask is used to determine the network ID and host ID from an IP address. A mask of 255.255.255.255 leaves zero bits for the host ID

effectively isolating the host from others on the physical segment

including its gateway.

2. Postel

J.

& Mogul

J. (1985). Internet Standard Subnetting Procedure. RFC 950. IETF. Section 2.1 discusses the structure of the subnet mask. A mask of all ones (255.255.255.255) logically implies a subnet with a single address

making communication with a separate gateway address impossible.

3. Kurose

J. F.

& Ross

K. W. (2021). Computer Networking: A Top-Down Approach (8th ed.). Pearson. Chapter 5

Section 5.4.2

"The IP Addressing Scheme

" details how a device uses its IP address and subnet mask to determine its subnet address. This process is used to decide whether to send a packet directly to a destination on the same subnet or to the default gateway for routing. With a /32 mask

the gateway is not on the same subnet.