Which of the following looks like a correct entry in the /etc/hosts file?

Viktor S.May 20, 2026

D is correct because /etc/hosts entries always lead with the IP address, followed by the canonical hostname, then any aliases. The file's parser expects that first field to be an address, so anything that puts a hostname first is just plain wrong.

Ola B.May 16, 2026

The format of /etc/hosts always puts the IP address first, then the hostnames that map to it, so D is the one that looks right to me. If you spin up any Linux box and open that file, you will see that pattern immediately, no guessing required. The reason options like A, B, C, and E trip people up is that they flip the order, putting hostnames before the address, which the resolver simply will not parse the way you expect. Quick lab check: cat /etc/hosts on any system you have handy and compare it against each option. Here is what I am curious about though, do you know why there are two names listed after the IP in option D, and what the difference between localhost and localhost.localdomain actually means in terms of how the system uses them?

Nina C.May 9, 2026

I keep going back to A on this one because when I think about how you read an address out loud, you say the name first and then the numbers, like saying your street name before the zip code, so "localhost 127.0.0.1 localhost.localdomain" just reads the most naturally to me and matches how I picture the file in my head from the study guide.