From the host 192.168.1.10, pinging a printer at 192.168.1.60 on the same /24 produces repeated lines reading `From 192.168.1.10 icmp_seq=1 Destination Host Unreachable`. What does this most directly indicate?
LPIC-1 Exam 102-500, objective 109. Networking fundamentals hard
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 The pinging host itself could not resolve 192.168.1.60 to a hardware address, so nothing on the local link answered ARP for it
Correct. The error is reported as coming from 192.168.1.10, the sender. For an on-link destination the kernel must resolve the target's MAC address first, and when ARP goes unanswered it fails the transmission with EHOSTUNREACH, which ping prints as Destination Host Unreachable.
Not correct The printer received the echo requests but its firewall dropped them
Wrong. A silently dropping firewall produces no message at all: ping simply reports no reply and shows 100% packet loss at the end of the run. An explicit unreachable error means something actively failed to deliver.
Not correct A router on the path has no route towards 192.168.1.0/24
Wrong on two counts. The destination is on the sender's own subnet, so no router is involved, and a router with no matching route replies with Destination Net Unreachable from its own address, not from 192.168.1.10.
Not correct The name of the printer could not be resolved by DNS
Wrong. A literal address was given, so no name resolution took place. A DNS failure ends ping before any packet is sent, with a message about an unknown host.
Why
Read the address at the start of a ping error line: it names whoever generated the failure. When that address is the sending host, the packet never left, which for a same-subnet destination almost always means ARP resolution failed because the target is powered off, absent or using a different address. `ip neigh show 192.168.1.60` confirms it, listing the entry as FAILED or INCOMPLETE. An unreachable message from a router address instead points at that router's routing table.
Where this comes from
- Cited
- manual page ping(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.
More questions on this objective
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- In IPv6, which address is the loopback address, equivalent in role to 127.0.0.1 in IPv4? machine-checked
- Which is the correct fully compressed form of the IPv6 address 2001:0db8:0000:0000:0000:ff00:0042:8329? machine-checked
- Which pairing of a service with its default port number is correct? machine-checked
- DNS normally uses UDP port 53. In which situation does a DNS client or server fall back to TCP on port 53? machine-checked