I've seen lots of issues in the past with either ISPs with non-compliant DNS services or routers with non-compliant DNS services (including transparent filtering/redirection). This can cause erroneous DNS responses to end up being cached, or resolvers being marked as unreachable.
I wonder if this is the issue here? I would debug this sort of issue with tcpdump and wireshark, using dig to generate DNS queries locally, using tcpdump to see what dnsmasq is sending out after the hang, and checking all previous requests and replies to make sure that dnsmasq is really doing something wrong. I'm not sure how to do this without a developer having the ability to reproduce the problem though. I'll set the Priority of the dnsmasq task to Medium for now, but if it turns out that a wide range of Ubuntu users are affected (ie. lots of routers or lots of ISPs) then we may need to review this. ** Changed in: dnsmasq (Ubuntu) Importance: Undecided => Medium -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to network-manager in Ubuntu. https://bugs.launchpad.net/bugs/994963 Title: DNS stops working after some time Status in “dnsmasq” package in Ubuntu: New Status in “network-manager” package in Ubuntu: New Bug description: Clean install of 12.04 and it works fine. After few hours, DNS suddenly stops working, no application can resolve domain names. If I manually put my ISP's nameserver (124.124.5.141) in /etc/resolv.conf things start working again. Remove it, and again no resolutions. Something's wrong with nm's dnsmasq I guess. Here are some things that might be useful- shaan@shaan-laptop:~$ cat /run/nm-dns-dnsmasq.conf server=124.124.5.141 server=124.124.5.140 server=124.124.5.136 shaan@shaan-laptop:~$ cat /etc/resolv.conf # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8) # DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN nameserver 127.0.0.1 I use a wirless router to connect to my ISP. Let me know if any other info is needed. ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: network-manager 0.9.4.0-0ubuntu3 ProcVersionSignature: Ubuntu 3.2.0-24.37-generic-pae 3.2.14 Uname: Linux 3.2.0-24-generic-pae i686 ApportVersion: 2.0.1-0ubuntu7 Architecture: i386 Date: Sat May 5 11:25:38 2012 IfupdownConfig: auto lo iface lo inet loopback InstallationMedia: Kubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423) IpRoute: default via 192.168.1.1 dev wlan0 proto static 169.254.0.0/16 dev wlan0 scope link metric 1000 192.168.1.0/24 dev wlan0 proto kernel scope link src 192.168.1.100 metric 2 NetworkManager.state: [main] NetworkingEnabled=true WirelessEnabled=true WWANEnabled=true WimaxEnabled=true ProcEnviron: LANGUAGE=en_IN:en TERM=xterm PATH=(custom, no user) LANG=en_IN SHELL=/bin/bash SourcePackage: network-manager UpgradeStatus: No upgrade log present (probably fresh install) nmcli-dev: DEVICE TYPE STATE DBUS-PATH eth0 802-3-ethernet unavailable /org/freedesktop/NetworkManager/Devices/1 wlan0 802-11-wireless connected /org/freedesktop/NetworkManager/Devices/0 nmcli-nm: RUNNING VERSION STATE NET-ENABLED WIFI-HARDWARE WIFI WWAN-HARDWARE WWAN running 0.9.4.0 connected enabled enabled enabled enabled disabled To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/dnsmasq/+bug/994963/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
