Which command displays current NAT translations on a Cisco router?

The command that displays current NAT translations on a Cisco router is "show ip nat translations." This command is essential for network administrators because it provides a real-time view of the active translations that the router is performing between private IP addresses and public IP addresses.

When you use this command, you can see details such as the inside local addresses, inside global addresses, outside local addresses, and outside global addresses. This information helps in troubleshooting connectivity issues, monitoring NAT usage, and verifying that NAT is functioning correctly.

The other commands listed do not pertain to NAT translations. For example, "show ip route list" pertains to the routing table and provides details on how packets are routed. "show ip interface brief" summarizes the status of interfaces but does not include NAT information. "show network topology" would typically provide insights into the layout of the network but would not include specifics about NAT translation. Hence, "show ip nat translations" is the appropriate choice for viewing NAT translations.