[SOLVED] Network connected, but no internet

rocketfuel · 12-31-2020, 12:24 AM

Hi all,

I'm beyond frustrated, and haven't been able to solve this problem with the help of Google.

I have no idea why, but after shutting down my machine and booting it back up, my network interfaces (both wired and wireless) are completely borked. Both wired and wireless connections will connect to my router (and Ubuntu will even see the printer on my network), but I can not connect to the internet. I've tried digging around in ip link, and the only thing odd that I can find is that the mode is set to "DORMANT" instead of "DEFAULT." Changing the mode does nothing.

My /etc/resolv.conf file reads:

Code:

nameserver 127.0.0.53
options edns0 trust-ad

I can ping 127.0.0.53, but all other pings (8.8.8.8, yahoo.com, etc.) fail with 100% packet loss.

One more odd thing: the system tray in the top right always shows a wired connection, and no longer shows my wireless connection.

I'm at my wits end. Any help would be appreciated.

EDIT: When booted into the LiveCD, networking works fine. All other machines on my network are working as expected.
I'm running Ubuntu 20.04, with the kernel updated to the latest version.

berndbausch · 12-31-2020, 01:04 AM

Show the output of ip address and ip route.

Also the Netplan configuration, which you find in files under /etc/netplan.

rocketfuel · 12-31-2020, 01:59 AM

Thank you for the help!

ip address:

Code:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: wlp0s20f3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether fc:44:82:3a:c3:a7 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.35/24 brd 192.168.1.255 scope global dynamic noprefixroute wlp0s20f3
       valid_lft 86389sec preferred_lft 86389sec
    inet6 fe80::6c9a:9895:39d9:7971/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: ipv6leakintrf0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
    link/ether d6:b0:39:90:9f:c2 brd ff:ff:ff:ff:ff:ff
    inet6 fdeb:446c:912d:8da::/64 scope global noprefixroute 
       valid_lft forever preferred_lft forever
    inet6 fe80::264e:3648:99b9:68cd/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
4: pvpnksintrf0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
    link/ether 36:af:1e:df:f4:0a brd ff:ff:ff:ff:ff:ff
    inet 100.85.0.1/24 brd 100.85.0.255 scope global noprefixroute pvpnksintrf0
       valid_lft forever preferred_lft forever
    inet6 fdeb:446c:912d:8da::/64 scope global noprefixroute 
       valid_lft forever preferred_lft forever
    inet6 fe80::9097:6a43:5bfc:5368/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

ip route:

Code:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: wlp0s20f3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether fc:44:82:3a:c3:a7 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.35/24 brd 192.168.1.255 scope global dynamic noprefixroute wlp0s20f3
       valid_lft 86389sec preferred_lft 86389sec
    inet6 fe80::6c9a:9895:39d9:7971/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: ipv6leakintrf0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
    link/ether d6:b0:39:90:9f:c2 brd ff:ff:ff:ff:ff:ff
    inet6 fdeb:446c:912d:8da::/64 scope global noprefixroute 
       valid_lft forever preferred_lft forever
    inet6 fe80::264e:3648:99b9:68cd/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
4: pvpnksintrf0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
    link/ether 36:af:1e:df:f4:0a brd ff:ff:ff:ff:ff:ff
    inet 100.85.0.1/24 brd 100.85.0.255 scope global noprefixroute pvpnksintrf0
       valid_lft forever preferred_lft forever
    inet6 fdeb:446c:912d:8da::/64 scope global noprefixroute 
       valid_lft forever preferred_lft forever
    inet6 fe80::9097:6a43:5bfc:5368/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

.config file in /etc/netplan:

Code:

# Let NetworkManager manage all devices on this system
network:
  version: 2
  renderer: NetworkManager

Also, if I run...

Code:

sudo dhclient wlp0s20f3

... the wireless icon immediately appears in the upper-right system tray, and I regain all functionality until a restart.

Thanks again for your help.

ondoho · 12-31-2020, 06:50 AM

Quote:

Originally Posted by rocketfuel

Also, if I run...

Code:

sudo dhclient wlp0s20f3

... the wireless icon immediately appears in the upper-right system tray, and I regain all functionality until a restart.

I know nothing about Ubuntu's netplan, so I have to phrase this very carefully, but I think this should be possible to make permanent, so it happens automatically at bootup.
Maybe by enabling the dhcpcd systemd service, maybe by letting netplan do that.

rocketfuel · 12-31-2020, 11:24 AM

I wound up removing network-manager with apt, and reinstalling it from a LiveCD. No joy. I'm wondering if I should have purged it and then reinstalled, so that it will take all of the config files with it. Or maybe I should just try reinstalling the system, although I'm hoping to avoid that if I can.

berndbausch · 12-31-2020, 11:47 AM

Quote:

Originally Posted by rocketfuel

Code:

2: wlp0s20f3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether fc:44:82:3a:c3:a7 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.35/24 brd 192.168.1.255 scope global dynamic noprefixroute wlp0s20f3
       valid_lft 86389sec preferred_lft 86389sec
    inet6 fe80::6c9a:9895:39d9:7971/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: ipv6leakintrf0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
    link/ether d6:b0:39:90:9f:c2 brd ff:ff:ff:ff:ff:ff
    inet6 fdeb:446c:912d:8da::/64 scope global noprefixroute 
       valid_lft forever preferred_lft forever
    inet6 fe80::264e:3648:99b9:68cd/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
4: pvpnksintrf0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
    link/ether 36:af:1e:df:f4:0a brd ff:ff:ff:ff:ff:ff
    inet 100.85.0.1/24 brd 100.85.0.255 scope global noprefixroute pvpnksintrf0
       valid_lft forever preferred_lft forever
    inet6 fdeb:446c:912d:8da::/64 scope global noprefixroute 
       valid_lft forever preferred_lft forever
    inet6 fe80::9097:6a43:5bfc:5368/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

ip address shows that the wireless interface has an IPv4 address. Interface 3 and 4 seem to be related to a Proton VPN tunnel; interface 4 has both an IPv4 and IPv6 address, whereas interface 3 has the same IPv6 address as interface 4 and no IPv4 address. I don't see a wired interface.

Given that, it depends on the routing table if you can access 8.8.8.8, but:

Quote:

ip route:

This is the output of ip address again, not ip route.

Quote:

.config file in /etc/netplan:

Code:

# Let NetworkManager manage all devices on this system
network:
  version: 2
  renderer: NetworkManager

This file is OK, but I believe its name needs to have a yaml extension, i.e. it should be named something.yaml. Since you use NetworkManager, I would also like to see the output of nmcli con and nmcli dev, i.e. the lists of all NetworkManager connections and devices.

To remove complexity while troubleshooting, I would disable the VPN tunnel for now.

tofino_surfer · 12-31-2020, 03:49 PM

For additional information please post the output of

Code:

$ ls -l /sys/class/net

Quote:

Also, if I run...

$ sudo dhclient wlp0s20f3

... the wireless icon immediately appears in the upper-right system tray, and I regain all functionality until a restart.

Does this mean full internet access is available ? Does this change the output of ip addr or ip route ? If so please post the changed output. You can use diff to search for changes in output by redirecting the output to files and using diff to compare the two files.

Also you appear to have interesting hardware as your wifi adapter is a multi-function device with a high slot number. Do you have a mini-ITX board with a lot of built-in hardware ?

rocketfuel · 12-31-2020, 05:03 PM

Quote:

This is the output of ip address again, not ip route.

My apologies, I was copy/pasting that in the early morning hours and wasn't paying attention. Here's ip route:

Code:

default via 100.85.0.1 dev pvpnksintrf0 proto static metric 98 
default via 192.168.1.1 dev wlp0s20f3 proto dhcp metric 600 
100.85.0.0/24 dev pvpnksintrf0 proto kernel scope link src 100.85.0.1 metric 98 
169.254.0.0/16 dev pvpnksintrf0 scope link metric 1000 
192.168.1.0/24 dev wlp0s20f3 proto kernel scope link src 192.168.1.35 metric 600

I've never heard of the nmcli con command before, and now I feel like we're getting somewhere. The output contains these two lines (as well as my usual wi-fi network):

Code:

pvpn-ipv6leak-protection  12f50eac-acd1-4ec6-ad75-cb835a533f55  dummy  ipv6leakintrf0 
pvpn-killswitch           8d71d923-3c19-41ff-b5e1-70f49f602fba  dummy  pvpnksintrf0

Those two (pseudo-interfaces?) are listed above my wi-fi when I restart NetworkManager (can't get online), but they are listed below my wi-fi connection when I run sudo dhclient <interface>. And the "killswitch" label seems to be a dead giveaway of what's going on.

Is there a way to manually remove those two from the list? I've purged protonvpn-cli from my system, but those two things remain.

rocketfuel · 12-31-2020, 05:13 PM

Quote:

Originally Posted by tofino_surfer

For additional information please post the output of

Code:

$ ls -l /sys/class/net

Does this mean full internet access is available ? Does this change the output of ip addr or ip route ? If so please post the changed output. You can use diff to search for changes in output by redirecting the output to files and using diff to compare the two files.

Also you appear to have interesting hardware as your wifi adapter is a multi-function device with a high slot number. Do you have a mini-ITX board with a lot of built-in hardware ?

ls -l /sys/class/net outputs:

Code:

lrwxrwxrwx 1 root root 0 Dec 31 15:04 ipv6leakintrf0 -> ../../devices/virtual/net/ipv6leakintrf0
lrwxrwxrwx 1 root root 0 Dec 31 15:04 lo -> ../../devices/virtual/net/lo
lrwxrwxrwx 1 root root 0 Dec 31 15:04 pvpnksintrf0 -> ../../devices/virtual/net/pvpnksintrf0
lrwxrwxrwx 1 root root 0 Dec 31 15:04 wlp0s20f3 -> ../../devices/pci0000:00/0000:00:14.3/net/wlp0s20f3

That's after I've run dhclient on the machine (so I can post this).

I'm pretty sure I followed some outdated instructions for installing the cli version of ProtonVPN, as I looked it up again, and the current instructions are completely different.

So, I'm fairly sure we know that ProtonVPN is the culprit, but the next question is: how do I remove it? I installed the current cli version hoping that I would be able to change the config of the old version, but that's not working. As I posted in the reply above, at this point, I'm just hoping to remove the errant interfaces manually and be done with it.

berndbausch · 12-31-2020, 05:26 PM

See the uninstall section at https://protonvpn.com/support/linux-vpn-tool/, or perhaps first protonvpn disconnect (of course, that's the new version, but worth the try).

There is still the problem that you have no trace of a wired interface, as confirmed by /sys/class/net. What type of wired interface do have - built into the PC, USB, other?

If built-in, please run lspci. USB: lsusb.

rocketfuel · 12-31-2020, 05:34 PM

My wired interface is a USB-C ethernet adapter that I bought for one of my MacBook Pros a couple years ago. It seems to work just fine, but is obviously not a permanent part of the machine.

And I've tried running the ProtonVPN uninstall instructions, but they did not work. I was messing with things before you helped me figure out that it was actually ProtonVPN's fault, so it's possible I changed something that could affect the uninstall. I believe I've changed all system config files back to their defaults though.

When the adapter is attached, the output of lsusb lists this:

Code:

Bus 002 Device 003: ID 0adb:1853 Realtek Semiconductor Corp. RTL8153 Gigabit Ethernet Adapter

computersavvy · 12-31-2020, 07:49 PM

Just a quick

If you have both wired and wireless active on the same network at the same time it is likely to cause communication problems. I suggest you do not connect the wired interface while trying to fix this problem to avoid those problems.
I have made it a practice to never have 2 interfaces on the same network active at the same time.

berndbausch · 12-31-2020, 07:58 PM

Your system is probably missing the driver for RTL8153. My guess is that it is not part of the default kernel, and you have to find it for example on the Realtek web site or your distro's repositories.

Regarding your VPN woes, you could try to remove the connections from the NM configuration under /etc/NetworkManager/system-connections/.

tofino_surfer · 01-01-2021, 12:18 AM

Quote:

So, I'm fairly sure we know that ProtonVPN is the culprit, but the next question is: how do I remove it?

Actually NetworkManager may be the culprit. You may not have to touch the VPN at all.

Quote:

Those two (pseudo-interfaces?) are listed above my wi-fi when I restart NetworkManager (can't get online), but they are listed below my wi-fi connection when I run sudo dhclient <interface>.

There are other daemons you could use besides NM.

Quote:

Maybe by enabling the dhcpcd systemd service

http://manpages.ubuntu.com/manpages/...dhcpcd5.8.html

tofino_surfer · 01-01-2021, 12:22 AM

Quote:

Your system is probably missing the driver for RTL8153. My guess is that it is not part of the default kernel, and you have to find it for example on the Realtek web site or your distro's repositories.

Actually the USB-C ethernet adapter may just not have been plugged in when they ran ls -l /sys/class/net. They stated that it is used occasionally and seems to work fine.

Quote:

My wired interface is a USB-C ethernet adapter that I bought for one of my MacBook Pros a couple years ago. It seems to work just fine, but is obviously not a permanent part of the machine.