nerdexam
GIAC

GSEC · Question #89

In trace route results, what is the significance of an * result?

The correct answer is D. No reply was received for a particular hop. In traceroute output, an asterisk (*) indicates that no ICMP TTL-exceeded response was received from a hop within the timeout window.

Networking and Core Concepts

Question

In trace route results, what is the significance of an * result?

Options

  • AA listening port was identified.
  • BA reply was returned in less than a second.
  • CThe target host was successfully reached.
  • DNo reply was received for a particular hop.

How the community answered

(31 responses)
  • A
    16% (5)
  • B
    6% (2)
  • C
    3% (1)
  • D
    74% (23)

Why each option

In traceroute output, an asterisk (*) indicates that no ICMP TTL-exceeded response was received from a hop within the timeout window.

AA listening port was identified.

Open listening ports are identified by port scanners like nmap, not by traceroute hop results.

BA reply was returned in less than a second.

Traceroute measures round-trip time in milliseconds and displays numeric values for fast replies, not an asterisk.

CThe target host was successfully reached.

Successful target host reachability is shown by a final hop returning the destination IP with a response time, not an asterisk.

DNo reply was received for a particular hop.Correct

Each traceroute probe sends a packet with an incrementing TTL value; when a router decrements TTL to zero it should return an ICMP 'Time Exceeded' message. An asterisk means that message never arrived - either the router is configured to drop ICMP, a firewall is blocking the response, or the packet was lost - so no reply was received for that specific hop.

Concept tested: Traceroute output interpretation and ICMP TTL

Source: https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/tracert

Topics

#traceroute#network diagnostics#ICMP#hop timeout

Community Discussion

No community discussion yet for this question.

Full GSEC Practice