Public bug reported: I have set up a small LAN in our office. The LAN uses a switch to connect computers, some of them Ubuntu desktops/laptops, with each other to share files and printers.
The LAN switch is connected to a broadband router which acts as a gateway to the internet for all machines connected to the LAN. So it is possible in normal situations for computers on the LAN to connect to each other *and* the internet without any problems. Additionally, these Ubuntu desktops/laptops are also configured to connect to the internet using a broadband USB modem when necessary. This option is used in one of two situations: 1. If the laptop is out of office and therefore not connected to the LAN 2. If the broadband router collapses due to some technical snag and is unable to offer any internet services. It is situation 2 that I am bothered about. In this situation Network Manager offers us the possibility of working either on the LAN or on the internet via the USB modem but not both. So if you want to surf the web, you have to disconnect from the LAN. If you want to use the LAN resources you have to disconnect the USB modem. This should not happen. I have installed wvdial and gnome-ppp on the machines. By setting the defaultroute and replacedefaultroute options in /etc/ppp/peers/wvdial-pipe and /etc/ppp/peers/wvdial and not setting any DNS entry in the eth0 configuration, I am able to access both the LAN resources and the internet. This is the way it should be. In my view, Network Manager (or Modem Manager) is unable to replace the default route when it connects. In my experience, this has been a long standing problem in various Ubuntu releases ever since Network Manager took over the network resources in lieu of /etc/networking/interfaces. So my suggestion is that Ubuntu should use wvdial/gnome-ppp, take the pain away from setting setuid permissions from wvdial and configure it to replace the default route at the time of installation. Network Manager could simply be a wrapper around wvdial to do this instead of trying unsuccessfully to reinvent the wheel. ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: network-manager 0.9.4.0-0ubuntu4.1 ProcVersionSignature: Ubuntu 3.2.0-32.51-generic 3.2.30 Uname: Linux 3.2.0-32-generic x86_64 NonfreeKernelModules: wl ApportVersion: 2.0.1-0ubuntu14 Architecture: amd64 CRDA: Error: [Errno 2] No such file or directory Date: Mon Oct 29 12:30:07 2012 InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425) IpRoute: default via 220.224.141.129 dev ppp0 proto static 220.224.141.129 dev ppp0 proto kernel scope link src 115.240.105.143 NetworkManager.state: [main] NetworkingEnabled=true WirelessEnabled=false WWANEnabled=true WimaxEnabled=true ProcEnviron: TERM=xterm PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: network-manager UpgradeStatus: No upgrade log present (probably fresh install) mtime.conffile..etc.NetworkManager.NetworkManager.conf: 2012-06-16T13:13:51.230640 nmcli-dev: DEVICE TYPE STATE DBUS-PATH ttyUSB0 cdma connected /org/freedesktop/NetworkManager/Devices/2 eth1 802-11-wireless unavailable /org/freedesktop/NetworkManager/Devices/1 eth0 802-3-ethernet disconnected /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 disabled enabled enabled ** Affects: network-manager (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug precise running-unity -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1072578 Title: Network Manager: eth0 and ppp0 together do not work To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1072578/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs