I am unable to visit most sites online in either firefox or chrome. I can access google docs so I am researching on windows 7 (dualboot) and rebooting into Ubuntu (recently upgraded to 16.04).

Test 0:

$ sudo /etc/init.d/dns-clean

(nothing happened)

Test 1:

$ dig microsoft.com
; <<>> DiG 9.10.3-P4-Ubuntu <<>> microsoft.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 2944
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 1

; EDNS: version: 0, flags:; udp: 512
;microsoft.com.         IN  A

microsoft.com.      896 IN  A
microsoft.com.      896 IN  A
microsoft.com.      896 IN  A
microsoft.com.      896 IN  A
microsoft.com.      896 IN  A

;; Query time: 102 msec
;; SERVER: 2001:558:feed::1#53(2001:558:feed::1)
;; WHEN: Tue Aug 29 14:54:43 EDT 2017
;; MSG SIZE  rcvd: 122

Test 2:

$ ping reddit.com
connect: Network is unreachable

Test 3:

$ less /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

Test 4:

$ less /etc/NetworkManager/NetworkManager.conf 



Test 5: Chrome

This site can’t be reached
www.reddit.com’s server DNS address could not be found.


Test 6: Firefox

Server not found
Firefox can’t find the server at www.reddit.com.
Check the address for typing errors such as ww.example.com instead of www.example.com
If you are unable to load any pages, check your computer’s network connection.
If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the Web.

Edit: Almost forgot, this seems to have started after I tried installing PlayOnLinux the other day. I uninstalled it but the problems persist.

Any thoughts?

Re: possible duplicate question : dns_probe_finished_nxdomain error caused by Ubuntu dns_probe_finished_nxdomain error caused by Ubuntu I clearly state in my question that the solution posed in the other thread of clearing the dns cache does not resolve my issue.

  • askubuntu.com/questions/844785/… poses a similar issue, but the resolution proposed there does not fix the issue. My attempt to use the solution from that thread is listed as test 0 in my question, and it did not resolve my issue. – Nick S Aug 29 '17 at 21:49
  • nekketsuuu I think the bug you linked is related, but it did not provide a solution for me. I actually moved over the weekend and now am able to use a wired connection and that is working fine, so the problem is with wireless only and I'm not going to spend any more time on it for now. If anyone else knows exactly what's going on and wants me to test a fix I'd be happy to though. – Nick S Sep 5 '17 at 15:56


Step 1. Open terminal and add below command

sudo nano /etc/dhcp/dhclient.conf

Step 2. Now add below line in file

supersede domain-name-servers;

Now, save file

Step 3. Restart the network

sudo service network-manager restart

Refresh your page and done.🙂🙂🙂

  • 4
    Really solved (!)... What the possible cause? A trojan? An UBUNTU upgrade? – Peter Krauss Jan 24 '18 at 15:42
  • Nope, I'm unlucky one – vladkras Sep 20 '18 at 11:08
  • 2
    This solved the issue for me but it would be nice to have this solution explained... what supersede domain-name-servers; does? – Andrea Vacondio May 23 '19 at 8:38
  • solved here too :) @AndreaVacondio it sets your DNS to Google's public DNS – Mr.P Dec 21 '19 at 17:24
  • Does not work for me. Kubuntu 20.04 going over a Netgear range extender. Normal Router has no problems to begin with. – lo tolmencre May 28 '20 at 0:39

For me it was flushing the dns cache that way:

sudo systemd-resolve --flush-caches

You can then check the statistics in order to make sure that your cache size is now zero.

sudo systemd-resolve --statistics

For me (Ubuntu 20.04), the only working solution was to add DNS servers of Google and OpenDNS.

I did it at computer level:

sudo vim /etc/resolv.conf

And added these lines (before other nameservers):


This can be also done at router level (for all devices):

  • Go to router management -> DNS -> Set primary DNS to and secondary DNS to

See https://linuxhint.com/opendns-vs-googledns/ for more info about choosing the DNS nameservers (and checking which server is faster in your location).

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