What command can be used to verify mapping between layer 2 MAC addresses and a gateway router?

The command that can be used to verify the mapping between layer 2 MAC addresses and a gateway router is the Address Resolution Protocol (ARP) command. ARP is essential for enabling devices within a local area network to discover the MAC addresses of other devices based on their IP addresses. When a device wants to communicate on the network but only knows the IP address of the destination, it sends out an ARP request to find out the corresponding MAC address.

This mapping is vital for data transmission within the same local network segment, as data is sent using MAC addresses at layer 2 of the OSI model. When you use the ARP command, you can view the ARP table, which lists the IP-to-MAC address pairings, including that of the gateway router. This allows network administrators to confirm that the mappings are correct and troubleshoot any connectivity issues related to these addresses.

Other commands like dig, ipconfig, and netstat serve different purposes. Dig is primarily a DNS lookup utility, ipconfig is used for network interface configurations, and netstat shows network connections and listening ports. While these tools are useful for various network tasks, they do not provide the functionality to show the MAC address mappings like ARP does.