CompTIA Network+ Practice Test

Which command would provide the local ARP table across all operating systems?

1. arp -v

2. arp -a

3. show arp -all

4. display arp table

The correct answer is: arp -a

The correct answer, which is arp -a, is used to display all entries in the Address Resolution Protocol (ARP) table on a local machine. This command shows all IP addresses and their corresponding MAC addresses that the system has resolved to its local ARP cache. The significance of using arp -a lies in its ability to provide a comprehensive view of the current network neighbors that the local machine has communicated with recently. This is vital for diagnosing network issues and verifying connectivity, as it reveals which devices are currently reachable on the same local network. Other choices may not accurately provide the same information across all operating systems. For instance, arp -v might imply a verbose output, but it does not guarantee the display of all ARP entries across different platforms. Commands like show arp -all and display arp table might be more specific to certain operating systems or network devices, like Cisco routers, and may not be universally applicable. Hence, arp -a is the more standardized command applicable across various operating systems for displaying the full local ARP table.