Spent 3 hours chasing a DNS issue that was just a typo in a config file

Last Tuesday I was migrating a client's site to a new host and their email started bouncing like crazy. Tore through DNS records, checked propagation, even called support for help. Turns out I typed 'mail.example.cm' instead of '.com' and wasted the whole afternoon. How long have you spent on something that dumb before finally spotting it?

3 comments

3 Comments

aliceharris8d ago

Oh man, that's brutal... I feel your pain on this one. I once spent a whole Saturday afternoon trying to figure out why an SSL cert wouldn't install, only to realize I'd copied the private key wrong by one character. Kept staring at the config file and my eyes just skipped right over it every single time. It's always the smallest dumbest thing that eats up hours like that.

shane_morgan8d ago

Honestly, it's wild how our brains just autocomplete what we expect to see instead of what's actually there. I'm curious though - when you were troubleshooting, did you actually diff the config against a known-good template, or were you just reading through it line by line? Because for me, that's the difference between catching a typo in 10 minutes versus 3 hours. Like, once you've been burned that bad once, you'd think we'd all learn to use a diff tool before anything else. But nope, we keep trusting our own eyeballs like they don't actively lie to us.

sean488d ago

And I swear I saw this study somewhere, maybe on HN, about how our brains literally fill in missing pieces based on context. Like you could have a config with a typo and your eyes will just glide right past it because your brain already decided what the correct thing should be. That's probably why diffing works so well, it forces you to look at the actual characters instead of what you think is there. I've caught stuff like a missing semicolon in a JSON file that way, something I'd have stared at for an hour otherwise. It's like your own brain is gaslighting you, man.