Which networking tool should a system administrator use to verify network connectivity?

The most appropriate tool for a system administrator to verify network connectivity is the ping command. This utility sends Internet Control Message Protocol (ICMP) Echo Request messages to a specified IP address or hostname and waits for an Echo Reply. By using ping, an administrator can check whether a device is reachable over the network and determine the round-trip time for messages sent from the source to the destination and back. If the ping command receives replies, it indicates that the network connection to the target device is functioning properly.

In contrast, the other options have different primary functions. The arp command is used for displaying and modifying the Address Resolution Protocol (ARP) cache, which maps IP addresses to MAC addresses, and is not specifically designed to test connectivity. The netstat command provides network statistics and details about open connections but does not verify connectivity directly. Lastly, the ipconfig command (or ifconfig in Linux environments) displays the current network configuration of a device, including IP addresses, subnet masks, and gateways, but it does not check the reachability of other devices; it is more about configuration than connectivity verification.