ICMP is used by which command line tool?

curl is an application-layer tool used to transfer data using protocols such as HTTP, FTP, and HTTPS, and does not use ICMP.

tcpdump is a packet capture and analysis tool that can capture ICMP traffic, but it does not generate or depend on ICMP to perform its function.

Traceroute works by sending packets with incrementally increasing TTL values; each router that decrements the TTL to zero returns an ICMP Time Exceeded (Type 11) message back to the sender. The final destination responds with an ICMP Echo Reply (Type 0) or ICMP Port Unreachable, allowing traceroute to record each hop. This makes ICMP fundamental to how traceroute discovers network path and latency.

nslookup is a DNS query tool that uses UDP or TCP on port 53 to resolve hostnames and has no dependency on ICMP.