wolfgang ziegler


„make stuff and blog about it“

Troubleshooting DNS Problems

April 7, 2017

So, last week that happened ...

Pingdom graph

I received a pingdom notification that my website had gone down. This had happened before (usually due to application issues), so I did what I usually did: headed over to the Azure Portal to see what was going on.

Only, my site was running just fine!

Accessing my site through its "original" URL http://wolfgangzieglerweb.azurewebsites.net brought it up immediately and showed no problems whatsoever. Also application health reports on Azure could not have been better.

So, it had to be a DNS issue.

Running nslookup confirmed this suspicion.

>nslookup wolfgang-ziegler.com

My domain wolfgang-ziegler.com just wasn't reachable any more.

Troubleshooting

I had bought, registered and configured this domain at asphostserver.myorderbox.com, so to narrow the problem down I tried their name servers directly with nslookup.

> nslookup wolfgang-ziegler.com asphostserver.myorderbox.com

Nothing. DNS did not resolve. It had to be a problem with their DNS servers.

In the mean time I had received yet another downtime notification. My second site ziegler-family.com DNS-registered with this very same provider had also gone down. Also due to DNS issues ...

Entering Support Hell

So I opened at support ticket with asphostserver hoping this would resolve easily since it was so clearly their fault. Well, ... not a bit of it. Their support member simply refused to consider the option that this could be a problem on their side. The conversation went back and forth, got a little heated over time but I am pretty sure, they never even checked if their DNS system had an issue.

I pointed out:

  • My DNS configuration at their system.
  • The URL to my sites running happily and without any issues on Azure.
  • My diagnostic findings using nslookup.

To absolutely no avail! Again, they simply refused to acknowledge the possibility of a problem on their side.

Now here's my questions to you guys out there:

  • Is there anything else I could have done to definitely prove whose problem this was?
  • Were my assumptions even correct?
  • Did I miss anything?

After a couple of hours of angry back and forth conversation, DNS for my sites suddenly went up again. Supposedly, nobody had changed anything. I know I definitely had not (because there was nothing I could have done) and the tech support person claimed the same for their party.

So the problem was gone, but it left back a bitter taste and unanswered questions. What had really gone wrong? And what if this happens again?

Cloudflare FTW!

As a consequence of this unpleasant experience I moved all my DNS related stuff over to Cloudflare and I have to say it has been a pleasure!

Disclaimer: Neither do I work for Cloudflare nor do I get anything out of it, promoting their services here. I just think one should give credit where it is due and it absolutely is in this case!

Configuring DNS has never been that easy in my experience:

  • I typed my existing domain name wolfgang-ziegler.com into a text box and started a scan. Cloudflare DNS scan

  • Cloudflare pulled out the existing DNS records. Cloudflare DNS configuration entries

  • Finally, I had to register Cloudflare's DNS servers with my domain at my existing host. Cloudflare name servers This can possibly still be a problem if asphostserver screws up again, but I am planning to move completely away from them and their crappy support in the near future.

All this is working with Cloudlflare's free tier* - plus, you also get basic DDos protection and CDN support.