Which command demonstrates a TCP traceroute?

Which command demonstrates a TCP traceroute?

• A. tcptraceroute www.example.com
• B. tracert -d example.com
• C. ping example.com
• D. nslookup example.com

Answer: (A)

To see the path to a destination using TCP probes, you need a traceroute tool that explicitly sends TCP packets rather than ICMP or UDP. The command shown uses TCP SYN probes to the destination (often on a commonly open port like 80) with increasing TTL values. Each hop along the route replies with a time-exceeded message (or the final host responds when the port is reachable), letting you map the sequence of routers between you and the target. This is what distinguishes a TCP traceroute from other ways of checking a path. The other commands don’t perform TCP-based traceroute. A Windows traceroute-style command typically uses ICMP Echo requests to discover hops, rather than TCP probes. Ping just checks basic reachability with ICMP echo requests and doesn’t reveal the path. nslookup queries DNS records, not the route to a host. So to observe a TCP traceroute, the dedicated TCP-traceroute tool is the appropriate choice.

To see the path to a destination using TCP probes, you need a traceroute tool that explicitly sends TCP packets rather than ICMP or UDP. The command shown uses TCP SYN probes to the destination (often on a commonly open port like 80) with increasing TTL values. Each hop along the route replies with a time-exceeded message (or the final host responds when the port is reachable), letting you map the sequence of routers between you and the target. This is what distinguishes a TCP traceroute from other ways of checking a path.

The other commands don’t perform TCP-based traceroute. A Windows traceroute-style command typically uses ICMP Echo requests to discover hops, rather than TCP probes. Ping just checks basic reachability with ICMP echo requests and doesn’t reveal the path. nslookup queries DNS records, not the route to a host. So to observe a TCP traceroute, the dedicated TCP-traceroute tool is the appropriate choice.