Exam XK0-005 topic 1 question 251 discussion

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)

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.

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.

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.