Introduction

This page is a list of important config files used with wireless networking.

Files

/etc/network/interfaces

This file stores networking interface settings.

IconsPage/tip.pngNetwork Manager cannot manage any interfaces that are named in this file. Network Manager has been the default way of managing network connections since Ubuntu 8.10 (Intrepid Ibex)

  • If you are not currently using Network Manager and would like to, delete or comment out (with a # at the start of each line) your interfaces except for the two lines referring to lo (this is an internal loopback). Since Ubuntu 8.10, this file will look similar to this:

      # The loopback network interface
      auto lo
      iface lo inet loopback
  • Do not use an auto stanza if you are using a PCMCIA deivce that you want to start automatically at boot-time. Add map <ath0> to the /etc/interfaces file. Your file should contain something similar to:

      #echo connects ath0 when device is hotplugged. using echo instead of grep allows any device to be brought up when hotplugged. Note this could cause a problem if a device is active and another one that is mapped is plugged in.
      mapping hotplug
              script echo
              map ath0
  • Check your routers settings to ensure it can accept another connection.
  • If you are running Ubuntu 8.04 (Hardy Heron) or earlier, you should have something similar to this:

    IconsPage/example.png

      # The loopback network interface
      auto lo
      iface lo inet loopback
    
      # This is a list of hotpluggable network interfaces.
      # They will be activated automatically by the hotplug subsystem.
      # With lines # out these don't work. If they were removed this would hotplug only eth0 when cable is plugged in with active network
      #mapping hotplug
      #       script grep
      #       map eth0
    
      #echo connects ath0 when device is hotplugged. using echo instead of grep allows any device to be brought up when hotplugged. Note this could cause a problem if a device is active and another one that is mapped is plugged in.
      mapping hotplug
              script echo
              map ath0
    
      #interface of ath0 device with wep setting (not all these lines are required but show you options that may be needed)
      iface <ath0> inet dhcp
      wireless-essid xxxx
      wireless-key xxxxx
      wireless-key xxxx-xxxx-xx (in certain situations a - is needed after every 4 characters to work)
      wireless-key1 xxxx (add a number after key to specify key number to use.)
      wireless-defaultkey 1 (specifies which key is default)
      wireless-key s:xxx (add s: in front of key if ascii form)
      wireless-key XXXXXXXXXX open|restricted (if using shared/restricted setting add this line)
    
      auto <ath0>

Other Resources

  • An /etc/network/interfaces sample - Part of LinuxPlanet's Connecting to a Wireless LAN with Linux, a tutorial by Carla Schroder.

  • This file has a manual page. Type man interfaces in a terminal to view it.

  • /usr/share/doc/ifupdown/examples/network-interfaces.gz. You can read through it with the cat command and then adding | less to the end of the command.

/etc/resolv.conf

This file stores Domain Name Server (DNS) settings including nameserver addresses, local domain names/search server addresses and some other advanced settings.

  • This file has a manual page. Type man resolv.conf in a terminal to view it.

/etc/modules

This file lists some of the modules that will be loaded into the kernel at boot-time. If a driver won't load at boot, you can add it to this list so that it does.

/etc/modprobe/

To enable specific configuration options for a driver create an appropriate config file in this folder eg. config.conf or [drivername].conf and add the options you want to set in this file.

notes

With the release of Ubuntu 11.10 and kernel 3.x.x some wireless drivers now no longer need 11n_disable and 11n_disable50 options. Theses options may actually cause the driver to fail to load. Check the /etc/modprobe.d/ folder for config files that contain option reference to your driver, for example

options iwlagn 11n_disable=1 11n_disable50=1

These options can be found in config.conf or [drivername].conf file eg. intel_11n_disable.conf or awlagn.conf.

/etc/modprobe.d/blacklist

If you don't want a driver to load at boot you add it to this list. Usually this is used if you have a driver conflict and/or you want to make sure a specific driver is used. Note: this method will not work unless the diver is a LKM (loadable kernel module) If driver/module was compiled into the base kernel, it will still load if blacklisted.


CategoryNetworking CategoryWireless

WifiDocs/WirelessTroubleShootingGuide/ConfigFiles (last edited 2013-12-14 00:22:35 by knome)