A traceroute crawls along, pausing for several seconds at each hop before the line appears, and the site's DNS servers are known to be slow. Which option makes traceroute print addresses only and skip the delay?
LPIC-1 Exam 102-500, objective 109. Networking fundamentals easy
Machine-checked — no person has signed for it. This question was read against the source cited below by an automated pass, which found no contradiction. That is a weaker claim than it sounds: the same kind of process wrote the question, so it can confirm its own mistake.
Treat it as a good draft rather than as settled fact, and read the source below before you rely on it. It is not used in mock exams here — only questions a person has signed for are.
How these questions are written — where each question comes from, what the verification ledger records, and what happens when one is found wrong.
The options
Correct -n
Correct. -n suppresses the reverse DNS lookup of each responding router, so hops are printed as numeric addresses as soon as the probe replies.
Not correct -q 1
Wrong for the stated cause. -q reduces the probes sent per hop from three to one, which makes the trace a little faster but does nothing about the name lookups that are causing the pauses.
Not correct -w 1
Wrong. -w shortens how long traceroute waits for a probe response. It speeds up unanswered hops, but hops that do answer still stall while their names are looked up.
Not correct -I
Wrong. -I switches the probes to ICMP echo requests instead of the default UDP datagrams. It changes what is sent, not how the results are displayed.
Why
-n is the conventional 'no name resolution' switch shared by traceroute, ping, ss, netstat and `route -n`, and it is the first thing to reach for when a network tool appears to hang between lines. Suppressing lookups also keeps the output honest, since a stale PTR record can otherwise suggest a router is somewhere it is not. Note that -n only affects display of the responding hops; the destination given on the command line is still resolved once at the start.
Where this comes from
- Cited
- manual page traceroute(8)
Practise this
Reading one question is not practice. The trainer will draw a short set from objective 109 and space the ones you get wrong.
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