TestOut LabSim A+ Certification Practice Exam

What would cause issues in a network communication if configured incorrectly?

1. Default gateway

2. Subnet mask

3. DHCP configuration

4. DNS server address

The correct answer is: Subnet mask

The subnet mask plays a critical role in network communication by determining which portion of an IP address represents the network and which part represents the host. If the subnet mask is incorrectly configured, devices on the network may not be able to correctly identify which IP addresses are on the same local network. This can lead to communication failures between devices that are supposed to be able to connect with one another, as they may see each other as being on different networks. For example, if two devices are configured with the same IP address but different subnet masks, they might not recognize each other as being on the same local network. This can prevent data packets from being sent or received properly, leading to potential disruptions in network services. While the other options are also critical aspects of network configuration that can lead to issues if set incorrectly, the subnet mask specifically affects the ability of devices to communicate within a local network immediately and can cause significant disruptions in a network's functionality.