Ubuntu
network-manager package

If it obtains the same nameserver address for multiple interfaces, NM fails to de-duplicate the list of addresses it gives to dnsmasq via nm-dns-dnsmasq.conf and just includes the same address multiple times

Bug #1015493 reported by Thomas Hood on 2012-06-20

This bug affects 1 person

Affects		Status	Importance	Assigned to	Milestone
	network-manager (Ubuntu)	Confirmed	Low	Unassigned

Bug Description

From /var/log/syslog:

Jun 20 10:03:25 tenerife dhclient: DHCPREQUEST of 192.168.2.103 on eth0 to 255.255.255.255 port 67
Jun 20 10:03:25 tenerife dhclient: DHCPOFFER of 192.168.2.103 from 192.168.2.254
Jun 20 10:03:25 tenerife dhclient: DHCPACK of 192.168.2.103 from 192.168.2.254
Jun 20 10:03:25 tenerife dhclient: bound to 192.168.2.103 -- renewal in 276336 seconds.
Jun 20 10:03:25 tenerife NetworkManager[1090]: <info> (eth0): DHCPv4 state changed preinit -> bound
Jun 20 10:03:25 tenerife NetworkManager[1090]: <info> address 192.168.2.103
Jun 20 10:03:25 tenerife NetworkManager[1090]: <info> prefix 24 (255.255.255.0)
Jun 20 10:03:25 tenerife NetworkManager[1090]: <info> gateway 192.168.2.254
Jun 20 10:03:25 tenerife NetworkManager[1090]: <info> nameserver '192.168.2.254'
Jun 20 10:03:25 tenerife NetworkManager[1090]: <info> Activation (eth0) Stage 5 of 5 (IPv4 Configure Commit) scheduled...
Jun 20 10:03:25 tenerife NetworkManager[1090]: <info> Activation (eth0) Stage 5 of 5 (IPv4 Commit) started...

# cat /var/run/nm-dns-dnsmasq.conf
server=192.168.2.254
server=192.168.2.254
---
ApportVersion: 2.0.1-0ubuntu8
Architecture: amd64
DistroRelease: Ubuntu 12.04
EcryptfsInUse: Yes
IfupdownConfig:
auto lo
iface lo inet loopback
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
IpRoute:
default via 192.168.20.254 dev eth0 proto static
169.254.0.0/16 dev eth0 scope link metric 1000
192.168.20.0/24 dev eth0 proto kernel scope link src 192.168.20.103 metric 1
192.168.20.0/24 dev wlan0 proto kernel scope link src 192.168.20.196 metric 9
NetworkManager.state:
[main]
NetworkingEnabled=true
WirelessEnabled=true
WWANEnabled=true
WimaxEnabled=true
Package: network-manager 0.9.4.0+git201206081144.2efeac8-0ubuntu1th1
PackageArchitecture: amd64
ProcEnviron:
TERM=xterm
PATH=(custom, user)
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcVersionSignature: Ubuntu 3.2.0-26.41-generic 3.2.19
Tags: precise
Uname: Linux 3.2.0-26-generic x86_64
UnreportableReason: This is not an official Ubuntu package. Please remove any third party package and try again.
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
mtime.conffile..etc.NetworkManager.NetworkManager.conf: 2012-07-04T09:47:16.565166
nmcli-dev:
DEVICE TYPE STATE DBUS-PATH
wlan0 802-11-wireless connected /org/freedesktop/NetworkManager/Devices/1
eth0 802-3-ethernet connected /org/freedesktop/NetworkManager/Devices/0
nmcli-nm:
RUNNING VERSION STATE NET-ENABLED WIFI-HARDWARE WIFI WWAN-HARDWARE WWAN
running 0.9.4.0 connected enabled enabled enabled enabled disabled

See original description

Tags:

Revision history for this message

Mathieu Trudel-Lapierre (cyphermox) wrote on 2012-07-09:

Please attach at least all of /var/log/syslog so that we can see NM bring up the interface fully. Even the output of 'nmcli con status id <your connection>' would be helpful here, once the connection is fully brought up.

Could it be that both IPv4 and IPv6 independently list 192.168.2.254 as your DNS server? That would be a configuration issue, as IPv6 should specify either an IPv6 address or no address at all.

Regardless, impact would AFAICT be minimal. Patches welcome ;)

Changed in network-manager (Ubuntu):
status:	New → Incomplete
importance:	Undecided → Low

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10: CRDA.txt

CRDA.txt Edit (257 bytes, text/plain)

apport information

tags:	added: apport-collected precise
description:	updated

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10: Dependencies.txt

Dependencies.txt Edit (3.1 KiB, text/plain)

apport information

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10: IpAddr.txt

IpAddr.txt Edit (1.1 KiB, text/plain)

apport information

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10: IwConfig.txt

IwConfig.txt Edit (508 bytes, text/plain)

apport information

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10: NetDevice.eth0.txt

NetDevice.eth0.txt Edit (439 bytes, text/plain)

apport information

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10: NetDevice.lo.txt

NetDevice.lo.txt Edit (206 bytes, text/plain)

apport information

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10: NetDevice.wlan0.txt

NetDevice.wlan0.txt Edit (487 bytes, text/plain)

apport information

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10: NetworkManager.conf.txt

NetworkManager.conf.txt Edit (105 bytes, text/plain)

apport information

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10: PciNetwork.txt

#10

PciNetwork.txt Edit (1.2 KiB, text/plain)

apport information

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Thomas Hood (jdthood) wrote on 2012-07-10: RfKill.txt

#11

RfKill.txt Edit (182 bytes, text/plain)

apport information

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10: WifiSyslog.txt

#12

WifiSyslog.txt Edit (8.9 KiB, text/plain)

apport information

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10: modified.conffile..etc.NetworkManager.NetworkManager.conf.txt

#13

modified.conffile..etc.NetworkManager.NetworkManager.conf.txt Edit (107 bytes, text/plain)

apport information

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10: nmcli-con.txt

#14

nmcli-con.txt Edit (1.2 KiB, text/plain)

apport information

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10: Re: NM writes duplicate lines in /var/run/nm-dns-dnsmasq.conf

#15

syslog.1 Edit (145.8 KiB, text/plain)

And here's syslog.1, since I notice that the log rotated the requested part of the syslog out of /var/log/syslog.

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10:

#16

$ cat /var/run/nm-dns-dnsmasq.conf
server=192.168.20.254
server=192.168.20.254
$ nmcli con status id vrfblx
GENERAL.NAME: vrfblx
GENERAL.UUID: da5d33ae-f25e-4039-9ac8-81ba3cdd30a7
GENERAL.DEVICES: wlan0
GENERAL.STATE: activated
GENERAL.DEFAULT: no
GENERAL.DEFAULT6: no
GENERAL.VPN: no
GENERAL.ZONE: --
GENERAL.DBUS-PATH: /org/freedesktop/NetworkManager/ActiveConnection/1
GENERAL.CON-PATH: /org/freedesktop/NetworkManager/Settings/3
GENERAL.SPEC-OBJECT: /org/freedesktop/NetworkManager/AccessPoint/0
GENERAL.MASTER-PATH: --
IP4.ADDRESS[1]: ip = 192.168.20.196/24, gw = 192.168.20.254
IP4.DNS[1]: 192.168.20.254
DHCP4.OPTION[1]: expiry = 1342512051
DHCP4.OPTION[2]: broadcast_address = 192.168.20.255
DHCP4.OPTION[3]: dhcp_message_type = 5
DHCP4.OPTION[4]: routers = 192.168.20.254
DHCP4.OPTION[5]: dhcp_lease_time = 604800
DHCP4.OPTION[6]: ip_address = 192.168.20.196
DHCP4.OPTION[7]: subnet_mask = 255.255.255.0
DHCP4.OPTION[8]: domain_name_servers = 192.168.20.254
DHCP4.OPTION[9]: network_number = 192.168.20.0
DHCP4.OPTION[10]: dhcp_server_identifier = 192.168.20.254

Changed in network-manager (Ubuntu):
status:	Incomplete → New

Revision history for this message

Thomas Hood (jdthood) wrote on 2012-07-10:

#17

I have both wired and wireless connections to the same LAN.

If I disable wireless then there is only one instance of the address left in nm-dns-dnsmasq.conf.

If I instead disconnect the Ethernet cable then there is only one instance of the address left in nm-dns-dnsmasq.conf.

So it seems that the two lines correspond to two interfaces, eth0 and wlan0, by which the (same) nameserver address can be reached.

Whatever the cause of the duplication might be, though, I'd think that NM should de-duplicate the list of addresses it gives to dnsmasq.

summary:

- NM writes duplicate lines in /var/run/nm-dns-dnsmasq.conf
+ If it obtains the same nameserver address for multiple interfaces, NM
+ fails to de-duplicate the list of addresses it gives to dnsmasq via nm-
+ dns-dnsmasq.conf and just includes the same address multiple times

Thomas Hood (jdthood) on 2012-07-12

Changed in network-manager (Ubuntu):
status:	New → Confirmed

Revision history for this message

Thomas Hood (jdthood) wrote on 2013-08-25:

#18

This bug still exists even though NM now communicates with dnsmasq over D-Bus.

Aug 25 21:31:33 sanrife dnsmasq[7027]: using nameserver 192.168.1.254#53
Aug 25 21:31:33 sanrife dnsmasq[7027]: using nameserver 192.168.1.254#53

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Ubuntunetwork-manager package

If it obtains the same nameserver address for multiple interfaces, NM fails to de-duplicate the list of addresses it gives to dnsmasq via nm-dns-dnsmasq.conf and just includes the same address multiple times

Bug Description

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Ubuntu
network-manager package