0

One of our projects encountered a strange issue today: the VPS server cannot reach a third party web service, because it cannot resolve its domain. When I SSH to the server and run dig, curl, traceroute, or ping to the web service's domain, I get the error Could not resolve host: %web.service.url%.

Interestingly, another server of the same hosting company located in the same region (Australia), has the exact same problem, so it must be a wider problem than just one particular server. Pinging the same service from local computer works fine, and other servers also do not have this issue. The guys from technical support weren't able to help us for several hours, their last message said:

"Your options are to contact the DNS provider you are using as the DNS servers are not providing any records for the domain."

I am not sure what is a DNS provider, and why they sound like we are using some custom one rather than something that they provide for their VPS servers. Could it be an issue between them and Australian ISP?

And most importantly, what are our options now, except moving everything to another hosting provider? Switching the third party web service is not an option at the moment.

EDIT: Below is the result of the dig %web.service.url%, when run from the server:

; <<>> DiG 9.9.5-4.3ubuntu0.1-Ubuntu <<>> %web.service.url%
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 35626
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1500
;; QUESTION SECTION:
;%web.service.url%.        IN  A

;; Query time: 1074 msec
;; SERVER: %server.ip.address%#53(%server.ip.address%)
;; WHEN: Thu Jul 20 09:19:44 UTC 2017
;; MSG SIZE  rcvd: 51
1

You've blocked out all the important information needed to actually do some testing for you. If the VPS servers are using DNS servers provided by the VPS host, and it fails to return records, then the problem should be with the VPS host.

A simple work around is to change the DNS settings on the VPS servers so that you use another DNS server. I typically use Google's DNS servers: 8.8.8.8 and 8.8.4.4

  • How can I do this? Is this done via SSH (I do have root access to it, if it's important), or via DNS settings (A, CNAME records, etc.), or something else? – parrker9 Jul 20 '17 at 9:37
  • It's done on the server. How to do that is dependent on what operating system it is running. It's typically going to be in the network configuration. Yes, via SSH. – Appleoddity Jul 20 '17 at 9:42
  • thank you very much for your help! If someone is like me, this article here has nice step-by-step instructions that worked on Ubuntu 14.10. – parrker9 Jul 20 '17 at 9:54
  • @parrker9 Keep in mind that different DNS servers might simply mean that there is an RFC violation that the software on the other servers plays with more gracefully. Changing the DNS servers is not always an option in places on your network and this problem may return in some fashion. In the future, please provide the name of the malfunctioning domain so that we can troubleshoot various scenarios. – Andrew B Jul 20 '17 at 13:36

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.