DNS – “Google, OpenDNS and Cloudflare – Flush” new skill learned

As an IT professional you can hardly miss working with DNS to some degree, and every now and then you have to go through the tedious task to change a public DNS record (like your website or mail server etc.) – my approach has always been to plan ahead and change the TTL (Time to live) to something smallish a few days in advance (and this IS still the way to go), but today I learned that there are a few tricks you can do to speed things up. The challenge has always been, if you needed to change a DNS record in a rush and the TTL was high then dns servers around the world might have cached this and your change would take forever to propagate – all depending of cause on how “popular” your domain is and all that jazz.

But love and behold, Google, OpenDNS and Cloudflare DNS services (some of the most used DNS services – famous for 8.8.8.8, 4.4.4.4, 1.1.1.1 and 208.67.222.222 among others) have implemented a “flush/clear” command, this will allow you to clear a DNS value from their cache and force it to be read again from the source (your DNS server/provider). How neat is that…

So even if you had a long TTL you can “cheat the clock” by fixing your DNS, and then flushing Google, OpenDns and Cloudflare DNS services – they are not the ONLY DNS services, so this may not solve all your problems – but as these services are among the more popular DNS services you may just cut a corner here.

“Magic” DNS cheat codes

This might just come in handy some day…