Scheduled Maintenance: We are aware of an issue with Google, AOL, and Yahoo services as email providers which are blocking new registrations. We are trying to fix the issue and we have several internal and external support tickets in process to resolve the issue. Please see: viewtopic.php?t=158230

 

 

 

[Solved] [Software] No internet access but connected to network

Linux Kernel, Network, and Services configuration.
Post Reply
Message
Author
gugu
Posts: 16
Joined: 2015-10-17 13:18

[Solved] [Software] No internet access but connected to network

#1 Post by gugu »

Hello everybody,

I am stacked with a network problem since a few days ago. Everything was working just fine when I rebooted my laptop. During the rebooting process it stacked saying “a stop job is running” mentioning something about “watchdog” (sorry, I don’t remember exactly and I don’t have any screenshot of that). The point is that I was in rush, and I forced the shut down by pressing the power button. When I restarted the laptop, both wifi and ethernet connections were connected (looking at network settings) but I have no internet access.

Looking for solutions on internet many suggested to check the DNS configurations. Actually when I checked the /etc/resolv.conf the nameserver was badly configured:

Code: Select all

# Generated by NetworkManager
nameserver ::1
I changed it to 8:8:8:8 but, once restarted the system, it went back to the wrong conf (::1).
I managed to avoid this behavior on reboot by doing the following after editing the resolv.conf:

Code: Select all

sudo chattr +i /etc/resolv.conf
After this, the file stayed with the correct configuration:

Code: Select all

# Generated by NetworkManager
nameserver 8:8:8:8
nameserver 8:8:4:4
However, internet is not working.
I can ping other devices in my network.

Code: Select all

guido@guido-debian:~$ ping 138.4.46.22
PING 138.4.46.22 (138.4.46.22) 56(84) bytes of data.
64 bytes from 138.4.46.22: icmp_seq=1 ttl=128 time=2.00 ms
64 bytes from 138.4.46.22: icmp_seq=2 ttl=128 time=1.77 ms
I can ping 8:8:8:8

Code: Select all

guido@guido-debian:~$ ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=112 time=2.59 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=112 time=1.62 ms
I cannot ping google.com or facebook.com

Code: Select all

guido@guido-debian:~$ ping google.com
ping: google.com: Name or service not known
guido@guido-debian:~$ ping facebook.com
ping: facebook.com: Name or service not known
IP configuration are ok as far as I can say (I use DHCP for IP address).

All the previous happens regardless I am using wifi or ethernet connection.

I have dual boot with Windows 10, everything works smoothly on windows.

I don’t know what to do, I red several threads about this on internet but either they didn’t solve my problem or they were too advanced and hardware specific (I am newby, it is difficult for me to adapt complex solutions).

Another thing I noticed is that I had a VPN configured to connect to my working network. It disappeared from network setting. I recently installed ProtonVPN and now the only VPN on my network setting is ProtonVPN. I could not say if the work VPN disappeared when the internet issue began or when I installed ProtonVPN. However I tried to uninstall ProtonVPN. Nothing change, and I can still see ProtonVPN in my network setting even if I cannot see it in installed packages/programs.

Any help or suggestion is appreciated.

Debian 10 buster, Kernel 4.19.0-22-amd64.

Thanks in advance…

Guido
Last edited by gugu on 2023-06-06 08:10, edited 3 times in total.

Aki
Global Moderator
Global Moderator
Posts: 2816
Joined: 2014-07-20 18:12
Location: Europe
Has thanked: 68 times
Been thanked: 382 times

Re: [Software] No internet access but connected to network

#2 Post by Aki »

Hello,

According to your previous post, the computer seems non able to resolve canonical names in IP addresses.

Perhaps the VPN configuration is still active and interfere with normal network operations.

I suggest you to follow a structured troubleshooting approach, documenting the commands (with their output) you use to replicate and analyse the issue. If you wish, you could also see here [1].

In the meanwhile, It could useful to take a look at the general hardware information of your computer (in anonymous form) with the command (the inxi program must be installed):

Code: Select all

inxi -Fxxxz
It could be useful to check system logs:

Code: Select all

journalctl -b0 --no-pager > log.txt
The previous command will generate a log file named log.txt that can be compressed and added as attachment to a follow-up message.

---
[1] https://www.redhat.com/sysadmin/beginne ... ting-linux
⢀⣴⠾⠻⢶⣦⠀
⣾⠁⢠⠒⠀⣿⡁ Debian - The universal operating system
⢿⡄⠘⠷⠚⠋⠀ https://www.debian.org
⠈⠳⣄⠀

Random_Troll
Posts: 444
Joined: 2023-02-07 13:35
Been thanked: 105 times

Re: [Software] No internet access but connected to network

#3 Post by Random_Troll »

gugu wrote: 2023-06-05 14:40I changed it to 8:8:8:8 but, once restarted the system, it went back to the wrong conf (::1).
The correct address for Google is 8.8.8.8 so your version won't work. You can tell NetworkManager to stop handling /etc/resolv.conf so you don't have to use the chattr hack: https://wiki.archlinux.org/title/Networ ... esolv.conf
gugu wrote: 2023-06-05 14:40I can still see ProtonVPN in my network setting
What do you mean by this, exactly? What do you see and where do you see it? What is "network setting"? Do you mean the NetworkManager graphical interface or are you referring to command line output? If the latter then please provide the actual commands and their full output.
Jeder nach seinen Fähigkeiten, jedem nach seinen Bedürfnissen.

gugu
Posts: 16
Joined: 2015-10-17 13:18

Re: [Software] No internet access but connected to network

#4 Post by gugu »

Hi @Aki and @Random_Troll, thank you for your answers and sorry for the late reply. I was working.

To summarize: I feel a real idiot… Replacing 8:8:8:8 with 8.8.8.8 everything works again. I still do not understand why NetworkManager reset resolv.conf file each reboot, but the chattr hack for now is working, and this afternoon after work I will try @Random_Troll suggestion and I’ll let you know. Do you have any idea about what could be the cause of this behavior?

Regarding the ProtonVPN, I was meaning the Network Manager graphical interface (see second screenshot). As you can see, ProtonVPN is not installed (see first screenshot). However, now I have simply manually removed the Proton VPN connection using the Network Manager GUI, and I configured again my work’s VPN. All working again as expected.

In brief, problem is fixed, and luckily the problem was my mistake using “:” instead of “.” (SORRY TO WASTE YOUR TIME)

If someone could help me to understand why resolv.conf resets on reboot I would appreciate it, but it’s more for sake of curiosity than for functionality.

Thanks a loot for your answers…
Attachments
Screenshot from 2023-06-05 17-27-43.png
Screenshot from 2023-06-05 17-27-11.png

User avatar
fabien
Forum Helper
Forum Helper
Posts: 605
Joined: 2019-12-03 12:51
Location: Anarres (Toulouse, France actually)
Has thanked: 60 times
Been thanked: 141 times

Re: [Solved] [Software] No internet access but connected to network

#5 Post by fabien »

gugu wrote: 2023-06-06 08:09If someone could help me to understand why resolv.conf resets on reboot I would appreciate it
gugu wrote: 2023-06-05 14:40(I use DHCP for IP address).
This is due to the dhclient settings. See /etc/dhcp/dhclient.conf

Code: Select all

request subnet-mask, broadcast-address, time-offset, routers,
        domain-name, domain-name-servers, domain-search, host-name,
        dhcp6.name-servers, dhcp6.domain-search, dhcp6.fqdn, dhcp6.sntp-servers,
        netbios-name-servers, netbios-scope, interface-mtu,
        rfc3442-classless-static-routes, ntp-servers;
DHCP can be prevented from requesting DNS by deleting domain-name-servers from the request field.

Random_Troll
Posts: 444
Joined: 2023-02-07 13:35
Been thanked: 105 times

Re: [Solved] [Software] No internet access but connected to network

#6 Post by Random_Troll »

Actually I think NetworkManager controls /etc/resolv.conf, hence the message at the top of the file.

NM can be told to use 8.8.8.8 as the default nameserver[0] or management of /etc/resolv.conf can be disabled completely.
Jeder nach seinen Fähigkeiten, jedem nach seinen Bedürfnissen.

User avatar
fabien
Forum Helper
Forum Helper
Posts: 605
Joined: 2019-12-03 12:51
Location: Anarres (Toulouse, France actually)
Has thanked: 60 times
Been thanked: 141 times

Re: [Solved] [Software] No internet access but connected to network

#7 Post by fabien »

Random_Troll wrote: 2023-06-06 15:52or management of /etc/resolv.conf can be disabled completely.
This is consistent with the fact that the network-manager package only suggests isc-dhcp-client. I thought it relied on it (I'm naive).

Post Reply