[SOLVED] Random issues with DNS resolving

madpet · 2018-06-21 09:53:20

I seem to have some issues with DNS resolving occasionally not working. I can browse the internet etc. without problems until suddenly, Chromium starts hanging at 'Resolving host...', sometimes even timing out with a ERR_NAME_RESOLUTION_FAILED error. Same happens in Firefox as well as when using git and other utilities. Sometimes everything starts working again after a few seconds, sometimes after minutes. It seems completely random.

When I set up Arch I installed broadcom-wl-dkms and used the wifi-menu (+wpa_supplicant) to connect to the internet. Then, after installing KDE, I switched to using their Connections module. Now I'm wondering if there's somehow multiple networking services battling each other for control of the resolver, and if that's the cause of the ruckus?

I tried running

getent hosts google.com

when everything worked (and it returned 2a00:1450:400f:809::200e google.com), but when I tried running the command during one of the hangups, it sat there for 10-15 seconds before closing without any output.

The content of my /etc/resolv.conf:

# Generated by NetworkManager
nameserver 89.150.129.22
nameserver 89.150.129.10

The content of my /etc/resolvconf.conf:

# Configuration for resolvconf(8)
# See resolvconf.conf(5) for details

resolv_conf=/etc/resolv.conf
# If you run a local name server, you should uncomment the below line and
# configure your subscribers configuration files below.
#name_servers=127.0.0.1%

The hosts line of /etc/nsswitch.conf is

hosts: files mymachines myhostname resolve [!UNAVAIL=return] dns

If I can provide any more debug data please let me know! I'm very new to Arch, but very much would like to stay

Last edited by madpet (2018-06-21 12:18:44)

V1del · 2018-06-21 10:26:44

What's your output for

systemctl list-unit-files --state=enabled
journalctl -b

? FWIW even without conflicting managers NetworkManager sometimes has problems while using its internal dhcp, try to switch that: https://wiki.archlinux.org/index.php/Ne … HCP_client

seth · 2018-06-21 10:29:18

systemctl list-unit-files --state=enabled
systemctl list-units | grep -iE '(net|dhcp|wicd|conn)'

Can you

dig archlinux.org
dig @8.8.8.8 archlinux.org
drill archlinux.org
drill @8.8.8.8 archlinux.org
ping archlinux.org
nslookup archlinux.org

madpet · 2018-06-21 11:09:40

Thanks for the quick replies! Here's the output:

➜  ~ systemctl list-unit-files --state=enabled

UNIT FILE                                   STATE  
autovt@.service                             enabled
dbus-org.freedesktop.NetworkManager.service enabled
dbus-org.freedesktop.nm-dispatcher.service  enabled
display-manager.service                     enabled
getty@.service                              enabled
lm_sensors.service                          enabled
NetworkManager-dispatcher.service           enabled
NetworkManager.service                      enabled
nfs-server.service                          enabled
postgresql.service                          enabled
sddm.service                                enabled
systemd-timesyncd.service                   enabled
remote-fs.target                            enabled

13 units listed.

The output from journalctl is gargantuan, but I've pasted the tail end of it here: https://hastebin.com/bivonoboqi.coffeescript

The next command gave this:

➜  ~ systemctl list-units | grep -iE '(net|dhcp|wicd|conn)'

sys-devices-pci0000:00-0000:00:01.3-0000:02:00.2-0000:03:00.0-0000:04:00.0-net-wlp4s0.device                         loaded active plugged   BCM4360 802.11ac Wireless Network Adapter                                    
sys-devices-pci0000:00-0000:00:01.3-0000:02:00.2-0000:03:06.0-0000:08:00.0-net-enp8s0.device                         loaded active plugged   RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller                    
sys-subsystem-net-devices-enp8s0.device                                                                              loaded active plugged   RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller                    
sys-subsystem-net-devices-wlp4s0.device                                                                              loaded active plugged   BCM4360 802.11ac Wireless Network Adapter                                    
NetworkManager.service                                                                                               loaded active running   Network Manager                                                              
systemd-timesyncd.service                                                                                            loaded active running   Network Time Synchronization                                                 
network-online.target                                                                                                loaded active active    Network is Online                                                            
network.target                                                                                                       loaded active active    Network                                                                      
nss-lookup.target                                                                                                    loaded active active    Host and Network Name Lookups

dig fails even with 8.8.8.8 as my dns

drill gives the same error with and without the @8.8.8.8

Error: error sending query: Could not send or receive, because of network error

ping archlinux.org gives this error:

ping: archlinux.org: Temporary failure in name resolution

nslookup archlinux.org fails with:

;; connection timed out; no servers could be reached

...and then, after a couple of minutes, everything works fine again... until it doesn't again, etc. etc. It's highly unreliable

V1del · 2018-06-21 11:18:01

The joiurnalctl -b output shouldn't have been that huge to not being able to post it to that pastebin site, unfortunately the excerpt you chose doesn't contain what I would've wanted to look out for. But FWIW posting

dmesg
journalctl -b --unit=NetworkManager

after the issue occured should be a smaller yet still telling excerpt.

Last edited by V1del (2018-06-21 11:59:50)

madpet · 2018-06-21 11:23:00

Alright here's the output from journalctl -b --unit=NetworkManager ran while the hangup occured: https://hastebin.com/xihesezomi.pl

And here's the output from dmesg at around the same time: https://hastebin.com/asupozolax.go

V1del · 2018-06-21 11:28:52

Just from a glance this really reads like the old dhcp issues, follow the link in my first answer and switch to dhclient restart NetworkManager reconnect if necessary and see if you can reproduce, post the NetworkManager journal command again should the issue return.

madpet · 2018-06-21 11:33:05

Okay, I'll try it. FYI the /etc/NetworkManager/conf.d/dhcp-client.conf mentioned in the link doesn't exist - the conf.d folder is empty. So I'll try creating the file

madpet · 2018-06-21 12:17:58

Almost an hour has passed without incident, so I think your solution worked V1del - thanks a lot!

Arch Linux

#1 2018-06-21 09:53:20

[SOLVED] Random issues with DNS resolving

#2 2018-06-21 10:26:44

Re: [SOLVED] Random issues with DNS resolving

#3 2018-06-21 10:29:18

Re: [SOLVED] Random issues with DNS resolving

#4 2018-06-21 11:09:40

Re: [SOLVED] Random issues with DNS resolving

#5 2018-06-21 11:18:01

Re: [SOLVED] Random issues with DNS resolving

#6 2018-06-21 11:23:00

Re: [SOLVED] Random issues with DNS resolving

#7 2018-06-21 11:28:52

Re: [SOLVED] Random issues with DNS resolving

#8 2018-06-21 11:33:05

Re: [SOLVED] Random issues with DNS resolving

#9 2018-06-21 12:17:58

Re: [SOLVED] Random issues with DNS resolving

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