You suspect that a gateway machine on your network has failed but you are unsure which machine. Which command will help locate the problem?

`ps` lists running processes on the local machine and provides no information about network connectivity or gateway status.

`netstat` displays network connections, routing tables, and interface statistics on the local machine but does not actively diagnose path failures to remote hosts.

`nslookup` (or `dig`) performs DNS lookups and resolves hostnames to IP addresses, which is not directly useful for identifying a failed gateway.

`ifconfig` (or `ip addr`/`ip link`) configures and displays information about network interfaces on the local machine, but it doesn't diagnose reachability to external gateways.

`traceroute` (or `tracepath`/`tracert` on some systems) shows the path that packets take to reach a destination, listing each router (hop) along the way. If a gateway fails, `traceroute` would stop at or before the failed gateway, indicating where the network path is broken.