NM + dnsmasq: server addresses in the wrong order

[Joe Barnett]

My corporate DHCP servers send 3 DNS servers: 2 internal ones, and a tertiary backup of 8.8.8.8. If I only connect wired or wireless, everything appears to work fine as long as I've added "strict-order" to /etc/NetworkManager/dnsmasq.d/options, but if I connect both, it appears to invert the first list sent to dnsmasq, and I end up unable to resolve internal hostnames.

nm-tool output:
- Device: eth0 [Auto eth0] ----------------------------------------------------
...
    DNS: 10.0.5.25
    DNS: 10.0.5.26
    DNS: 8.8.8.8
- Device: wlan0 [Auto COMPANY AP] -----------------------------------------------
...
    DNS: 10.0.5.25
    DNS: 10.0.5.26
    DNS: 8.8.8.8

syslog output:
Apr 1 16:04:42 taplop NetworkManager[1744]: <info> ((null)): writing resolv.conf to /sbin/resolvconf
Apr 1 16:04:42 taplop dnsmasq[2155]: setting upstream servers from DBus
Apr 1 16:04:42 taplop dnsmasq[2155]: using nameserver 8.8.8.8#53
Apr 1 16:04:42 taplop dnsmasq[2155]: using nameserver 10.0.5.26#53
Apr 1 16:04:42 taplop dnsmasq[2155]: using nameserver 10.0.5.25#53
Apr 1 16:04:42 taplop dnsmasq[2155]: using nameserver 10.0.5.25#53
Apr 1 16:04:42 taplop dnsmasq[2155]: using nameserver 10.0.5.26#53
Apr 1 16:04:42 taplop dnsmasq[2155]: using nameserver 8.8.8.8#53

nslookup outputs hitting dnsmasq vs/ internal nameserver directly:
$ nslookup rb 127.0.1.1
Server: 127.0.1.1
Address: 127.0.1.1#53

Non-authoritative answer:
Name: rb.company.com
Address: [www.company.com]

$ nslookup rb 10.0.1.25
Server: 10.0.1.25
Address: 10.0.1.25#53

rb.company.com canonical name = rbp01.company.com.
Name: rbp01.company.com
Address: 10.0.1.35

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: network-manager 0.9.6.0-0ubuntu7
ProcVersionSignature: Ubuntu 3.5.0-27.46-generic 3.5.7.7
Uname: Linux 3.5.0-27-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 2.6.1-0ubuntu10
Architecture: amd64
Date: Mon Apr 1 16:05:18 2013
IfupdownConfig:
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2010-04-19 (1078 days ago)
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Release Candidate amd64 (20100419.1)
IpRoute:
 default via 10.9.5.1 dev eth0 proto static
 10.9.5.0/24 dev eth0 proto kernel scope link src 10.9.5.59 metric 1
 10.9.5.0/24 dev wlan0 proto kernel scope link src 10.9.5.58 metric 9
 169.254.0.0/16 dev wlan0 scope link metric 1000
MarkForUpload: True
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
SourcePackage: network-manager
UpgradeStatus: Upgraded to quantal on 2012-10-05 (178 days ago)
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH
 eth0 802-3-ethernet connected /org/freedesktop/NetworkManager/Devices/2
 wlan0 802-11-wireless connected /org/freedesktop/NetworkManager/Devices/0
nmcli-nm:
 RUNNING VERSION STATE NET-ENABLED WIFI-HARDWARE WIFI WWAN-HARDWARE WWAN
 running 0.9.6.0 connected enabled enabled enabled enabled disabled

[Mathieu Trudel-Lapierre (cyphermox)]

Tentatively confirming; I think I have an idea what might be causing this, though not necessarily how to fix just yet. Assigning to myself so I can take a look at the code to figure it out.

[Joe Barnett (thejoe)]

awesome, let me know if I can help test anything

[Thomas Hood (jdthood)]

As of Ubuntu 12.10 you can't deal with bug #1003842 ("dnsmasq sometimes fails to resolve private names in networks with non-equivalent nameservers") by turning on "strict-order" in /etc/NetworkManager/dnsmasq.d/. The reason is that, since 12.10, NM sends nameserver addresses to dnsmasq over D-Bus; and in that case the order of the nameservers is not preserved.

    https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1003842/comments/49

The best workaround is to comment out "dns=dnsmasq" in /etc/NetworkManager/NetworkManager.conf and then restart network-manager.