My API key for Akismet was suddenly unconfirmed by reason of not being able to reach akismet.com My provider had indeed troubles with their primary DNS so I switched to the google public one. (18.104.22.168). This is a server not a browsing machine so I don’t have any privacy worries.
Long storry short, I changed the DNS and expected the problem to go away. Next day I was happy to find out that it didn’t. I pinged akismet.com from the console, tried http connection to it with links everything was fine. For good measure I tried other DNS entries, tried a mtr to akismet.com but still everything was fine and the key in Akismet Configuration refused to work.
Than, after a slap on my forehead I remembered THIS. Right, after
service httpd stop
service httpd start
Everything went back to normal.