The DNS propagation waiting game
Posted in: DNS, Monitoring, Speed Up Tips   -   August 20, 2013

This post is by Dan Wall who is the founder of WhatsMyDNS.net.

We all know that feeling, you’ve made changes to your DNS records and what you once had total control over, your precious network setup – has been sent out there for the unknown Internet to decide the fate of.

You can never be quite sure of when the changes will be reflected to all of your customers, all you can do is cross your fingers and hope for the best.

Fortunately, tools like whatsmydns.net let you check DNS propagation and monitor your changes as they propagate throughout the world. This can at least give you some confidence that your changes are working as planned.

The what if…?

Once you’ve made your changes strange thoughts start to run through your mind…

What if I’ve made a mistake? What if I’ve sent all our customers to a black hole on the Internet? What if I’ve accidentally set the corporate network to SPF hard fail?

The list of things that could go wrong when it comes to DNS is almost endless, it’s impossible to think of them all.

The mistake

Mistakes happen to the best of us, it’s a fact of life and will surely happen to you sooner or later.

When you actually have made a mistake it feels like the world is going to end, your boss comes in screaming as to why they can’t access the company website and you get angry customers on the phone! All the while losing potential customers, sales and hurting your brand.

You just wish that you could have quickly fixed the issue before anybody had ever noticed.

The problem

It’s not over yet though, the worst part is yet to come. You make the required changes, double, no – triple check and then once again the fate of your website or email is in the hands of the Internet.

Try explaining to your boss that the company website “should come back online in the next 72 hours” – ouch!

The solution

Unfortunately, the sad truth is that there’s no real fix for this problem other than making sure that you don’t get yourself into this situation to start with.

Luckily, this is really easy to do! All you need to do is plan ahead. If you know that you’re going to need to make important DNS changes then you should strongly consider lowering the TTL (Time To Live) of your domain name. A recommended TTL value for making changes is 300 seconds, which is equal to 5 minutes.

With a TTL of 5 minutes the boss is unlikely to notice any issues, but feel free to choose a value that is appropriate for your situation.

Of course, as with all good things, there’s a trade-off. What will happen is that your authoritative nameservers will get additional requests as downstream nameservers query your nameserver more often which may increase load.

Once you’re happy that all of your changes have gone through, set your domain’s TTL back to its previous setting and you’ll be good to go. It really is that simple and can save a lot of pain and lost business.

Global_DNS_Propagation_Checker_-_What_s_My_DNS_


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  • http://blog.justindorfman.com jdorfman

    Great post Dan. Love your service, I use it almost daily!

  • http://www.MaxCDN.com/ Chris Ueland / MaxCDN

    This is also a great tool for testing out geo-dns services where CDNs or DNS providers use a layer of DNS indirection in different geographies to return different records. Thanks for the post and the free service, Dan!

  • koeksght

    Cloudfare has this sorted if you use it right 😉 Registered a new .org domain and got it index by Google in 15 minutes.