Connection issue after installing NordVPN on Lubuntu 20.04

Question

I'm using Lubuntu LXQt desktop version 20.04, and everything was ok until installing NordVPN. during the using NordVPN, I have no issue with the connection. but when the laptop is idle for some time and when I back to browser it seems there is no connection. so I test it with:

ping 4.2.2.4

And I get this error:

ping sendmsg operation not permitted

Even I use sudo or do login/logout, just restarting entire the system could help me to back to the working network. obviously there is another issue. so:

What is the problem and how I can fix it?

NordVPN outputs:

$ nordvpn status
    Status: Disconnected
$ nordvpn settings
    Technology: OpenVPN
    Protocol: UDP
    Kill Switch: disabled
    CyberSec: disabled
    Obfuscate: disabled
    Notify: enabled
    Auto-connect: disabled
    DNS: disabled

Solution

I realized that the Linux firewall block the NordVPN firewall and the NordVPN killswitch stop the connection, so I should stop the Linux firewall and re-run the NordVPN service and the connection will get back on track.

By using the following command:

sudo ufw enable && sudo ufw disable && sudo /usr/bin/systemctl restart nordvpnd

Comments

[ldias]

Is ufw enabled? If it is disable it and see if it works: sudo ufw disable

[AmerllicA]

@user68186, I'm using the nordvpn command-line utility.

[AmerllicA]

@ldias, what is the ufw and why I should disable it?

[ldias]

ufw stands for uncomplicated firewall and is essentially a frontend for iptables. It is installed by default on Ubuntu. A firewall can sometimes block a VPN connection so disabling it might work. Run: sudo ufw disable and try again and see if anything changes

[AmerllicA]

Dear @user68186, I don't know why the senior users of AskUbuntu ask the PO to edit. you are senior to me. please edit my post just like you want it. definitely, I have problems in this community. thanks.

[AmerllicA]

Dear @ldias, I do it now. and I should wait to see, is it worked or not. also, I implemented what this post said. maybe this setting will settle the issue.

[user68186]

@ldias I use nordvpn with ufw without any problems and without any rules specific for the VPN, but it is always good to check if disabling ufw solves the problem.

[AmerllicA]

Dear @user68186, I have no output from nordvpn, after installing it I faced this issue. the main problem is this: connection lost

[user68186]

Can you access the Internet from browser with nordvpn disabled? What happens if you enable nordvpn using the command nordvpn connect command? What happens if you disable nordvpn manually by using nordvpn disconnect command after connecting to nordvpn first? It looks like nordvpn gets improperly disconnected and using the connect then disconnect then conncect again may fix it.

[Sebastian]

OpenVPN has problems reconnecting after a system suspend. When you say your laptop is idle, is it possible that it went into suspend or hibernation?

[AmerllicA]

@Sebastian, it just gonna show screen saver, neither both of your said situations.

[pierrely]

also you can connect to any countriers server, eg US with nordvpn connect US

[pierrely]

I have been back to losing the internet connectin when disconnecting and reconnecting usb hubs.... and have had to reboot.... today I have discovered that running 'service network-manager start' (either as sudo or putting in password on authorisation popup) before disconnecting the usb hub (with the ethernet adapter on it) allows me to then reconnect the hub (or another) and the connection picks up. Nordvpn , set to autoconnect then picks up too. better than rebooting all the time.