Arch Linux

archifer

Member

Registered: 2019-07-08

Posts: 49

[SOLVED] Lost internet connection

I was just watching youtube videos doing nothing and suddenly I have lost internet connection completely even on my phone, I experience such issue for the first time, when I tried to `ping` something I got this reply:

ping: sendmsg: Operation not permitted

I have googled an answer to apply a fix

iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT

And it worked but I still have no idea what or why did it happen? Am I ok with the applied commands above? Should I change anything back?

P.S. I don't use Firewall.

Last edited by archifer (2019-12-12 11:46:15)

seth

Member

Registered: 2012-09-03

Posts: 51,270

Re: [SOLVED] Lost internet connection

I doubt that "resetting" a (non-used itfp) local IP filter is any related to "even on my phone" - it's more likely that either your AP/router or ISP had a drop-out and the performed changes are merely coincidental to a self-fix of that situation.

You might want to inspect the actual IP tables in case this happens again, but I'm willing to bet your right arm that ping failed because NM put the NIC in scanning mode or did other shenanigans.

P.S. I don't use Firewall.

What else can you tell us about the network?
Wired or Wifi?
Are you (supposed to be) the only user?
How do you configure the network (networkmanager, dhcpcd - maybe you're accidentally running multiple NIC controlling services concurrently?)
…

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ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 19,793

Re: [SOLVED] Lost internet connection

Explain "Even on my phone".  Did you mean using your phone tethered or as a wireless hotspot for your Arch Box?  Or did you mean that the neither your phone or computer can use the internet through your router? I assume Seth is thinking the later.

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Sometimes it is the people no one can imagine anything of who do the things no one can imagine. -- Alan Turing
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archifer

Member

Registered: 2019-07-08

Posts: 49

Re: [SOLVED] Lost internet connection

I doubt that "resetting" a (non-used itfp) local IP filter is any related to "even on my phone" - it's more likely that either your AP/router or ISP had a drop-out and the performed changes are merely coincidental to a self-fix of that situation.

You might want to inspect the actual IP tables in case this happens again, but I'm willing to bet your right arm that ping failed because NM put the NIC in scanning mode or did other shenanigans.

P.S. I don't use Firewall.

What else can you tell us about the network?
Wired or Wifi?
Are you (supposed to be) the only user?
How do you configure the network (networkmanager, dhcpcd - maybe you're accidentally running multiple NIC controlling services concurrently?)
…

I'm using the network router wifi (wired connection) with VPN and I'm the only user, this is my home network and PC and phone connected to it. This is just the first accident like that for two years. I was just wondering if the commands applied above are appropriate and safe? Since I applied it the network seems fine.

Last edited by archifer (2019-12-08 09:29:20)

archifer

Member

Registered: 2019-07-08

Posts: 49

Re: [SOLVED] Lost internet connection

Explain "Even on my phone".  Did you mean using your phone tethered or as a wireless hotspot for your Arch Box?  Or did you mean that the neither your phone or computer can use the internet through your router? I assume Seth is thinking the later.

The phone and the computer are connected to the same network via VPN but even if I turned VPN off there were still no network only appeared after I ran the commands above. Even rebooting the router didn't help.

Last edited by archifer (2019-12-08 09:36:13)

seth

Member

Registered: 2012-09-03

Posts: 51,270

Re: [SOLVED] Lost internet connection

If you "don't use Firewall" those commands did exactly nothing at all. They're in this case completely unrelated to whatever happened to your network.
Coincidence ist not the same as correlation, let alone causation.
Alternatively something™ (your VPN?) did setup some IP filter, BUT: since your phone was affected independently, chances for that case are somewhere around 0%.

Sidenote: please ask questions about "appropriate and safe" *before* you hit some stuff you don't understand into a terminal… you don't want to hear a "nope" as a reply after the effect.

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How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

archifer

Member

Registered: 2019-07-08

Posts: 49

Re: [SOLVED] Lost internet connection

If you "don't use Firewall" those commands did exactly nothing at all. They're in this case completely unrelated to whatever happened to your network.
Coincidence ist not the same as correlation, let alone causation.
Alternatively something™ (your VPN?) did setup some IP filter, BUT: since your phone was affected independently, chances for that case are somewhere around 0%.

Sidenote: please ask questions about "appropriate and safe" *before* you hit some stuff you don't understand into a terminal… you don't want to hear a "nope" as a reply after the effect.

yes I agree and so as I didn't apply any rules before I just ran iptables -F to drop it to default values, rebooted and it seems fine along with VPN connection.

khaithang

Member

Registered: 2019-04-07

Posts: 5

Re: [SOLVED] Lost internet connection

I faced this problem and i was using VPN too. This is related to the VPN (openvpn under the hood) service. They enable firewall and sets some filters, if the VPN closes gracefully, it undoes everything as well. The problem occurs when the VPN mulfunctions for some reason or doesn't properly shut downs.
I fixed it by restarting the VPN.
Don't send any kill -9 signal to the VPN process