How to Fix Incorrect /etc/hosts Entry Blocking Website Access

XK0-005 By islever Editorial Last updated Aug 23, 2026

Short answer

B Remove the entry for portal.comptia.org from the local hosts file.

Question

A Linux administrator is troubleshooting an issue in which users are not able to access https://portal.comptia.org from a specific workstation. The administrator runs a few commands and receives the following output: # cat /etc/hosts 10.10.10.55 portal.comptia.org # host portal.comptia.org portal.comptia.org has address 192.168.1.55 #cat /etc/resolv.conf nameserver 10.10.10.5 Which of the following tasks should the administrator perform to resolve this issue?

Update the name server in resolv.conf to use an external DNS server.
Remove the entry for portal.comptia.org from the local hosts file. Correct Answer
Add a network route from the 10.10.10.0/24 to the 192.168.0.0/16.
Clear the local DNS cache on the workstation and rerun the host command.

Key Takeaways

The question tests understanding of the Linux name-resolution order (hosts file before DNS) and the trap of assuming DNS cache or routing is the root cause.

When a local /etc/hosts entry maps a domain to the wrong IP, it overrides DNS resolution and prevents users from reaching the correct site. Removing the stale or incorrect hosts entry restores proper DNS-based resolution.

Common mistake: Many candidates choose D (clear DNS cache) because they focus on the host command output, forgetting that /etc/hosts is consulted before any DNS query or cache.

Expert Analysis

Why the Answer Is Correct

The /etc/hosts file is consulted before DNS by default on Linux systems (glibc nsswitch.conf order files dns). The entry 10.10.10.55 portal.comptia.org forces the workstation to use the wrong IP, so HTTPS to the real portal fails. Removing that line lets the resolver fall through to the DNS server, which correctly returns 192.168.1.55. As community member [3] notes, the conflict between the hosts file and DNS is the exact cause of the outage.

Why the Other Options Are Wrong

Option A (change nameserver) is irrelevant because the hosts file overrides DNS regardless of which nameserver is configured. Option C (add a route) is a distractor; routing is not the issue since the wrong IP is being selected before any packet leaves the host. Option D (clear DNS cache) is tempting but ineffective — the host command already bypasses the cache and still shows the correct DNS answer, proving the problem is the local hosts override, as commenter [2] implicitly acknowledges.

Community Comment Notes

Commenter [1] correctly states the resolution order: "your system checks host file first then pings the dns." Commenter [4] reinforces that removing the conflicting entry lets the workstation rely on DNS. Commenter [2] raises a valid point about the host output differing from the hosts file, but ultimately the fix is still to remove the overriding hosts entry so DNS can take over.

Official Reference

These links open the official vendor documentation in a new tab.

Exam Strategy

Whenever a Linux troubleshooting question shows both /etc/hosts and DNS output, first check the name-resolution order. If the hosts file contains an entry for the target domain, assume it is overriding DNS and look for the option that removes or corrects that entry.

Community Votes

67%

33%

67% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 4 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 4

makuziker 👍 3 Answered D

I argue that B does not make sense here. We can see that there is a local DNS entry mapping portal.comptia.org -> 10.10.10.55. But, the actual DNS resolution, from the host command, is different, portal.comptia.org -> 192.168.1.55. Something is taking priority over the local DNS in /etc/hosts. If we delete the entry in /etc/hosts, I doubt it will resolve our connection problem, because the system is getting its DNS resolution from something else, possibly a cache. I think we should flush the local DNS cache and try again. We should also verify what is the correct IP it should resolve to. Perhaps we SHOULD also remove the entry from /etc/hosts, but for the reason that the private DNS server (at 10.10.10.5) should be responsible for resolving DNS, not workstations.
sterguy 👍 3 Answered B

I believe it is B because your system checks host file first then pings the dns if host file doesn't have a entry for what your looking for.
Monty97 👍 2 Answered B

The issue is likely caused by a conflicting entry for portal.comptia.org in the local /etc/hosts file, which is mapping the domain to an incorrect IP address (10.10.10.55). The correct IP address for portal.comptia.org according to DNS resolution is 192.168.1.55. Option A: Updating the name server in resolv.conf to use an external DNS server wouldn't resolve the issue since the issue is related to the local hosts file. Option C: Adding a network route wouldn't address the DNS resolution issue. Option D: Clearing the local DNS cache and rerunning the host command might help if there were changes made to DNS configurations, but the root cause here is the conflicting entry in the hosts file. Removing the entry for portal.comptia.org from the local hosts file (/etc/hosts) will allow the system to resolve the domain through DNS properly.
NastyNutsu 👍 1 Answered B

as it, the internal users can still access the website if they can route to 192.168.1.55 internally. External users may face issues if the DNS resolves to the internal address 192.168.1.55. the issues here is /etc/hosts is overriding the DNS resolution. by removing the conflicting entry from the local hosts file, the workstation will reply on the DNS server to resolve the address of the website, which should provide the correct IP address (192.168.1.55)

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