Disconnecting and reconnecting docking station breaks DNS
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
network-manager (Ubuntu) |
New
|
Undecided
|
Unassigned |
Bug Description
I'm not sure which package this bug should be submitted to as service troubleshooting in the latest few Ubuntu releases is a jumbled mess.
Anyway, here's how to repro the problem:
- Lenovo Carbon X1 2016 (4th gen), OneLink+ docking station
- Ethernet connected to docking station
- Disconnect docking station
- Reconnect docking station
From this point on all DNS requests fail. Workarounds I found so far:
- reboot the machine (not really a solution)
- sudo system network-manager restart (requires sudo access)
- usually in older releases I'd just poke around with the resolver config files, but anything I do seems to be ignored now so I gave up and posted a bug instead.
Here's the journalctl log for NetworkManager, followed by an example of the problem:
nico@nico-
-- Logs begin at Sun 2017-02-19 00:10:56 GMT. --
Feb 20 20:22:41 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:22:42 nico-lenovo-ubuntu dnsmasq[6728]: setting upstream servers from DBus
Feb 20 20:22:42 nico-lenovo-ubuntu dnsmasq[6728]: using nameserver 194.168.
Feb 20 20:22:42 nico-lenovo-ubuntu dnsmasq[6728]: using nameserver 194.168.
Feb 20 20:22:42 nico-lenovo-ubuntu dnsmasq[6728]: using nameserver 194.168.
Feb 20 20:22:42 nico-lenovo-ubuntu dnsmasq[6728]: using nameserver 194.168.
Feb 20 20:22:42 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:22:42 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:22:43 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:22:43 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:40 nico-lenovo-ubuntu dhclient[6736]: receive_packet failed on lan1: Network is down
Feb 20 20:27:40 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:40 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:40 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:40 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:40 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:40 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:40 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:40 nico-lenovo-ubuntu dnsmasq[6728]: setting upstream servers from DBus
Feb 20 20:27:40 nico-lenovo-ubuntu dnsmasq[6728]: using nameserver 194.168.
Feb 20 20:27:40 nico-lenovo-ubuntu dnsmasq[6728]: using nameserver 194.168.
Feb 20 20:27:40 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:40 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:40 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:56 nico-lenovo-ubuntu dhclient[7552]: DHCPREQUEST of 192.168.0.21 on lan1 to 255.255.255.255 port 67 (xid=0x1e395bfb)
Feb 20 20:27:57 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:27:59 nico-lenovo-ubuntu dhclient[7552]: DHCPREQUEST of 192.168.0.21 on lan1 to 255.255.255.255 port 67 (xid=0x1e395bfb)
Feb 20 20:28:00 nico-lenovo-ubuntu dhclient[7552]: DHCPACK of 192.168.0.21 from 192.168.0.1
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu dhclient[7552]: bound to 192.168.0.21 -- renewal in 36449 seconds.
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
Feb 20 20:28:00 nico-lenovo-ubuntu dnsmasq[6728]: setting upstream servers from DBus
Feb 20 20:28:00 nico-lenovo-ubuntu dnsmasq[6728]: using nameserver 194.168.
Feb 20 20:28:00 nico-lenovo-ubuntu dnsmasq[6728]: using nameserver 194.168.
Feb 20 20:28:00 nico-lenovo-ubuntu dnsmasq[6728]: using nameserver 194.168.
Feb 20 20:28:00 nico-lenovo-ubuntu dnsmasq[6728]: using nameserver 194.168.
Feb 20 20:28:00 nico-lenovo-ubuntu NetworkManager[
nico@nico-
;; connection timed out; no servers could be reached
nico@nico-
^Cnico@
Using domain server:
Name: 8.8.8.8
Address: 8.8.8.8#53
Aliases:
google.com has address 216.58.198.238
google.com has IPv6 address 2a00:1450:
google.com mail is handled by 10 aspmx.l.google.com.
google.com mail is handled by 30 alt2.aspmx.
google.com mail is handled by 20 alt1.aspmx.
google.com mail is handled by 40 alt3.aspmx.
google.com mail is handled by 50 alt4.aspmx.
nico@nico-
Command "print" is unknown, try "ip route help".
nico@nico-
default via 192.168.0.1 dev lan1 proto static metric 100
default via 192.168.0.1 dev wifi0 proto static metric 600
169.254.0.0/16 dev lan1 scope link metric 1000
192.168.0.0/24 dev lan1 proto kernel scope link src 192.168.0.21 metric 100
192.168.0.0/24 dev wifi0 proto kernel scope link src 192.168.0.26 metric 600
nico@nico-
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.0.1 0.0.0.0 UG 100 0 0 lan1
0.0.0.0 192.168.0.1 0.0.0.0 UG 600 0 0 wifi0
169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 lan1
192.168.0.0 0.0.0.0 255.255.255.0 U 100 0 0 lan1
192.168.0.0 0.0.0.0 255.255.255.0 U 600 0 0 wifi0
nico@nico-
[sudo] password for nico:
nico@nico-
google.com has address 172.217.23.14
google.com has IPv6 address 2a00:1450:
google.com mail is handled by 20 alt1.aspmx.
google.com mail is handled by 50 alt4.aspmx.
google.com mail is handled by 30 alt2.aspmx.
google.com mail is handled by 10 aspmx.l.google.com.
google.com mail is handled by 40 alt3.aspmx.
nico@nico-
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.0.1 0.0.0.0 UG 100 0 0 lan1
0.0.0.0 192.168.0.1 0.0.0.0 UG 600 0 0 wifi0
169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 lan1
192.168.0.0 0.0.0.0 255.255.255.0 U 100 0 0 lan1
192.168.0.0 0.0.0.0 255.255.255.0 U 600 0 0 wifi0
ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: network-manager 1.2.6-0ubuntu1
ProcVersionSign
Uname: Linux 4.8.0-38-lowlatency x86_64
ApportVersion: 2.20.3-0ubuntu8.2
Architecture: amd64
CurrentDesktop: XFCE
Date: Mon Feb 20 20:34:07 2017
IfupdownConfig:
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback
InstallationDate: Installed on 2016-10-20 (122 days ago)
InstallationMedia: Ubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.2)
IpRoute:
default via 192.168.0.1 dev lan1 proto static metric 100
default via 192.168.0.1 dev wifi0 proto static metric 600
169.254.0.0/16 dev lan1 scope link metric 1000
192.168.0.0/24 dev lan1 proto kernel scope link src 192.168.0.21 metric 100
192.168.0.0/24 dev wifi0 proto kernel scope link src 192.168.0.26 metric 600
NetworkManager.
[main]
NetworkingEnab
WirelessEnable
WWANEnabled=false
SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
nmcli-dev:
DEVICE TYPE STATE DBUS-PATH CONNECTION CON-UUID CON-PATH
lan1 ethernet connected /org/freedeskto
wifi0 wifi connected /org/freedeskto
lan0 ethernet unavailable /org/freedeskto
lo loopback unmanaged /org/freedeskto
nmcli-nm:
RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN
running 1.2.6 connected started full enabled enabled enabled enabled disabled
If it helps, commenting out/removing
# dns=dnsmasq
from
/etc/NetworkMa nager/NetworkMa nager.conf
makes the problem go away.