Question

How to fix the March 2017 Ubuntu DNS resolution issues

As of March 20th, many Ubuntu users across the web were suddenly having DNS resolution issues pop up in their applications due to a bad update pushed out by Canonical (the maintainers of Ubuntu) which breaks DNS resolution after a few hours of uptime. Here’s the bug report where the issue was reported and triaged:

https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/1674532

This may have resulted in failures of your CMS to update/install plugins/install themes, failures to connect to external APIs, and/or error messages similar to the following:

Warning: file_get_contents(): php_network_getaddresses: getaddrinfo failed: No address associated with hostname
Could not resolve host: downloads.wordpress.org
cURL error 6: Could not resolve host: example.com in....

Fortunately Canonical has since been able to resolve the issue, but affected systems must update to acquire the fix. To do that, you’ll need DNS working, so if it’s currently down please first reboot your Droplet. Once DNS resolution is working as normal, please run:

sudo apt-get update
sudo apt-get upgrade

Then you can check your versions to ensure you’ve got the right ones. This can be done with:

sudo dpkg -l | grep "GNU C Library" | awk '{print $3}'

If you’re on Ubuntu 16.X, you should see output similar to the following:

# sudo dpkg -l | grep "GNU C Library" | awk '{print $3}'
2.23-0ubuntu7
2.23-0ubuntu7
2.23-0ubuntu7

If you’re on Ubuntu 14.X, you should see output similar to the following:

# sudo dpkg -l | grep "GNU C Library" | awk '{print $3}'
2.19-0ubuntu6.11
2.19-0ubuntu6.11

If you’re on Ubuntu 12.X, you should see output similar to the following:

# sudo dpkg -l | grep "GNU C Library" | awk '{print $3}'
2.15-0ubuntu10.17
2.15-0ubuntu10.17

If you see older versions of those packages, you’ll need to upgrade per the previous instructions to avoid this issue.

If you have further questions, please don’t hesitate to comment below or open a ticket! We’re happy to help :)

Regards, Darian Platform Support Advocate

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I had to edit the /etc/resolve.conf file to add name servers as recommended above.

That gave me the opportunity to upgrade Ubuntu. As suggested above, I am seeing the proper results.

sudo dpkg -l | grep “GNU C Library” | awk ‘{print $3}’ 2.23-0ubuntu7 2.23-0ubuntu7 2.23-0ubuntu7 2.23-0ubuntu7 2.23-0ubuntu7

Unfortunately, after a few hours the problem returns. Is there a fix for this situation?

I spent 2 entire days working on this issue and fixed it in less than 2 minutes once I’d found this article. I was such a pain in the ass to figure out what was happening. Eventually I did realize that something was messed up with DNS but I spent 6 hours trying to find a problem with the UFW that didn’t exist. So stressful…

I performed the procedure, but the problem is still occurring.

CURL error 28: Resolving timed out after 10521 milliseconds

My droplet is on the NYC1 server running a WordPress 4.7 on 16.04 image.

I am having some trouble still. DNS works but is extremely slow (~1min), I was able to sudo apt-get update and sudo apt-get upgrade and confirmed right version – but still having dns issues even after reboot (pinging any url fails, but pinging ip’s works fine)

I am having some trouble still. DNS works but is extremely slow (~1min), I was able to sudo apt-get update and sudo apt-get upgrade and confirmed right version – but still having dns issues even after reboot (pinging any url fails, but pinging ip’s works fine)

This worked to get plugin updates and the dashboard news feeds working again on my WordPress site. Thank you!

Thank you.

Did the update, but still seeing the issue, do we need to reset anything after the update? :)

php_network_getaddresses: getaddrinfo failed: No address associated with hostname (0)

Thank you, I hope this has solved my issue. We have been having intermittent issues connecting to the aws api as of 21st March receiving the ‘cURL error 6: Could not resolve host: example.com’ error message.

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