8

I have just started picking up Ubuntu and have come across an issue I cannot seem to resolve. I have been using linux for a few days and it has been working fine. All of a sudden, today I was not able to connect to the internet.

I cannot connect to any website. It shows I am connected to my home's wireless network. My internet is working on other devices. In fact, I have both windows and linux on my machine and it is working on my windows machine. Firefox aside, even when i do ping google.com, it returns ping: google.com: Temporary failure in name resolution.

Here are some of the things I have tried/diagnosed but haven't worked:

  • Updating software (cannot connect to internet so no updates)
  • Restarting my computer
  • Changing my DNS to 8.8.8.8 and 8.8.8.4
  • Connecting to other wifi networks (can connect, but same issue of no internet)
  • nmcli dev status returns:
DEVICE        TYPE      STATE        CONNECTION
wlo1          wifi      connected    My Home Network
ipv6leakintrf0 dummy    connected    pvpn-ipv6leak-protection
docker0       bridge    connected    docker0
p2p-dev-wlo1  wifi-p2p  disconnected --   
enp...        ethernet  unavailable  --
lo            loopback  unmanaged    --
  • Based on the p2p-dev-wlo1 wifi-p2p disconnected -- portion above, I found this question Ubuntu 20.04 says that Wi-Fi is connected but doesn't allow me to connect to the internet . Similar to the person asking that, my default gateway is also 192.168.0.1. I changed it manually in the network settings window, but even then my default route and DNS remained the same i.e. 192.168.0.1. I tried changing it by first doing sudo route del default gw 192.168.0.1 and then sudo route add default gw 192.168.1.1 but my second operation was denied due to siocaddrt network is unreachable.
  • I have looked at several other questions about this issue but are not appropriate to my situation.

I am at a loss as to what else I can do. Any input is appreciated. I will try to answer the questions to the best of my ability. Thank you a lot in advance.

I am using ubuntu 20.04. My network controller is from Intel. ifconfig -a gives me the following information for wlo1 (which is assume has to do with wireless):

wlo1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.0.108  netmask 255.255.255.0  broadcast 192.168.0.255
        inet6 fe80::3a14:f4d:3085:1ee4  prefixlen 64  scopeid 0x20<link>
        ether 40:ec:99:f7:a2:88  txqueuelen 1000  (Ethernet)
        RX packets 419  bytes 35272 (35.2 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 138  bytes 20200 (20.2 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

EDIT: Based on comments raised i did some further diagnostics. The issue happens on both ethernet and wifi.

> ping -c4 192.168.0.1
4 packets transmitted, 3 received, 25% packet loss, time 3026ms rtt min/avg/max/mdev = 9.068/80.681/204.124/87.600 ms

> ip l | grep $(ip r | awk '/default/ {print $5}' ) | awk '{print $2, $4, $5}'
wk '{print $2, $4, $5}' 
wlo1: mtu 1500

Note: I manually wrote most of the above outputs since my ubuntu machine doesn't have internet. So pardon me if there is an error.

codingray
  • 81
  • Try rebooting your router, too. – user535733 Nov 01 '21 at 12:44
  • I have turned it off and on again. I didnt mention it but my other devices are all working with the same network. – codingray Nov 01 '21 at 12:50
  • Yes, some-devices-working-but-others-mysteriously-not is a classic symptom of a router that has exhausted it's RAM and needs to be rebooted. Next: Does wired networking function? Use rfkill to check for a block? Try a LiveUSB's "Try Ubuntu" environment to see if there is any difference? – user535733 Nov 01 '21 at 12:53
  • I tried it and doesn't seem like it. My network window says 'Wired' is connected at 10 mbps. Sadly, I cannot test my ethernet cable on my other working laptop as it doesnt have an ethernet port. – codingray Nov 01 '21 at 13:02
  • Can you ping your router successfully using it's IP address? – user535733 Nov 01 '21 at 13:04
  • Im sorry but how do i do that? – codingray Nov 01 '21 at 13:06
  • ping -c4 192.168.0.1. Try both wired and wireless separately. I'm assuming that your router is at 192.168.0.1 from your output -- if the router actually has a different address, use the correct address instead. After four pings, the system will show you a summary. A good result is something like 4 packets transmitted, 4 received, 0% packet loss, time 2004ms – user535733 Nov 01 '21 at 13:08
  • 4 packets transmitted, 3 received, 25% packet loss, time 3026ms rtt min/avg/max/mdev = 9.068/80.681/204.124/87.600 ms in both cases (apologize for delay, had to transfer the output over) – codingray Nov 01 '21 at 13:22
  • Look at the logs! sudo journalctl -b 0 -u NetworkManager. Read man journalctl. What's your WiFi MTU? ip link show, or ip l | grep $(ip r | awk '/default/ {print $5}' ) | awk '{print $2, $4, $5}'. WiFi MTU should be 1492, not 1500 – waltinator Nov 01 '21 at 13:41
  • Comments are designed for US to ask YOU questions about your Question. You should [Edit] your question to add information. By updating your Question, and using the formatting buttons, you make all the information available to new readers. People shouldn't have to read a long series of comments to get the whole story. – waltinator Nov 01 '21 at 13:42
  • @waltinator noted. Apologize for the messiness. For the logs, what am I looking out for? – codingray Nov 01 '21 at 14:11
  • Can you add info about your adapter: laptop, internal or external; usb type if external; usb cable type if external; usb cable length if external; and most importantly the chipset? I say chipset because you mention that you're just starting which implies a scavenged box and some chipsets are more pesty than others when demanding cpu support and don't have fully flushed-out drivers for them. BCM4323 is one such chip that I'm having issues with right now and it also the effect of spiking cpu so badly that I can't type. It takes down the router as well. – neil Dec 14 '21 at 01:35
  • Had the same issue. This answer helped to solve it. https://askubuntu.com/a/1358237 – user2984127 Feb 22 '22 at 09:09
  • I have this issue on 22.04 after the system froze, but also there was some update in Ubuntu Base. Still figuring out. – Ondra Žižka Sep 16 '22 at 11:50

3 Answers3

9

If you look into the output of the command nmcli device

you can see a connection named pvpn-ipv6leak-protection which is created by device ipv6leakintrf0(Type-dummy). This issue is caused by Proton VPN to prevent IP leak when you accidentally turn off your system or disconnect from your network without disconnecting the VPN. As long as that connection remains, it will block access to internet on your device.

The solution is to run the following command on the terminal(in this case)

nmcli connection delete pvpn-ipv6leak-protection
Arjun K Shibu
  • 951
2

For me, this kind of problem could be solved by using the Google Public DNS IP addresses in the /etc/resolv.conf file:

sudo cp /etc/resolv.conf /etc/resolv.conf.bak
sudo nano /etc/resolv.conf

nameserver 8.8.8.8
nameserver 8.8.4.4

I got the hint for this solution from the following YouTube video:

https://www.youtube.com/watch?v=iergu6AIook

Also see

Janux
  • 151
1

Try running:

sudo dhcpcd

From the man-page(formatting my own):

 dhcpcd is an implementation of the DHCP client specified in RFC 2131.
 dhcpcd gets the host information (IP address, routes, etc) from a DHCP
 server and configures the network interface of the machine on which it is
 running.  dhcpcd then runs the configuration script which writes DNS
 information to resolvconf(8), if available, otherwise directly to
 /etc/resolv.conf.  If the hostname is currenly blank, (null) or localhost
 then dhcpcd sets the hostname to the one supplied by the DHCP server.
 dhcpcd then daemonises and waits for the lease renewal time to lapse.
 Then it attempts to renew its lease and reconfigure if the new lease
 changes.

It helped me.

Error404
  • 7,440
name
  • 11
  • Hi, I didn't manage to fix it. I just reinstalled my ubuntu but thanks for answering. Hopefully this can help someone in the future if they come across a similar issue. – codingray Jan 31 '22 at 14:09