Ubuntu internet problem: connected to router, ping doesn't work (no problems with Android and Windows)

[stustd]

The internet connection problem with my Laptop (Ubuntu/Mate) has the following symptoms:

• After reboot no internet connection problems whatsoever.
• However, after suspend mode (e.g. closing the lid) and login:
  • From Linux console:
    • No ping response when pinging outside world (e.g. www.google.com).
    • Perfect ping response when pinging within local network.
  • No access to internet (e.g. browsing).
  • Laptop is connected (wired and wireless) to (Virgin Media Superhub 2) router (machine name with correct IP addresses mentioned in router's list);
  • Can successfully ping from the router to the outside world.

No internet connection problems with all other devices (Windows, Android). Help much appreciated.

 

[Rob]

Can you ping the outside world using an ip address? For instance, try to ping 8.8.8.8 (google's public dns).

You can also try to query a domain using google's dns like dig @8.8.8.8 www.linux.org

Edit:
If that works, then add something like this to your /etc/resolv.conf file (this would use google's public dns)

nameserver 8.8.4.4
nameserver 8.8.8.8

 

[stustd]

Indeed, I think it's a nameserver problem. I can't reach the mentioned nameservers 8.8.8.8 and 1.1.1.1 by their IP addresses. Also, if I set these as nameservers in /etc/resolv.conf, after restarting the /etc/init.d/{networking,network-manager} the resolv.conf nameservers are reset to a local IP address (127.0.0.53)... (Also there are no nameservers specified in the router).

From the output of "systemd-resolve --status" I learn that it sees the ISP (Virgin Media)'s nameservers:

"""
Link 3 (wlp3s0)
...
DNS Servers: 194.168.4.100
194.168.8.100
"""

Yet something stop the machine to use them...

 

[Rob]

Can you ping the ips? Also, can you ping your router's ip?

 

[stustd]

I've decided to reboot and after suspending a few times everything keeps functioning as normal... All thanks for your help.

 

[Rob]

ah, nice - great to hear

 

[Jeremyb]

Sounds like Network Manager messing the connection up when it enables wifi power management, the usual solution is to

sudo sed -i 's/wifi.powersave = 3/wifi.powersave = 2/' /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf
systemctl restart network-manager.service

as I posted at https://askubuntu.com/a/910186/300665

The first part of the askubuntu.com answer can be ignored as the content of the /etc/NetworkManager/NetworkManager.conf file was changed because of bug reports and it usually only affected USB wifi devices