
  FAQ

    1. Q: I want to use ifplugd with my PCMCIA device, but ifplugd quits
       when it doesn't find eth0, when I have not inserted the card. What
       can I do?
       A: Use the -f switch. This is not very clean however, since
       modprobe is called on each cable detection query of ifplugd to
       load a module for the network device. This is suboptimal. You
       should probably run ifplugd only when the card is really inserted.
    2. Q: I am using the -f switch, but the kernel logs are getting
       filled with messages like "modprobe: modprobe: Can't locate module
       eth0". What can I do?
       A: Make sure you have a line like alias eth0 off in your
       /etc/modules.conf
    3. Q: When the cable is unplugged and the interface shut down it is
       still available with ifconfig and markes as UP. Why this?
       A: ifplugd cannot detect the link beat with a shut down interface
       on certain (most as of kernel 2.4.19) network drivers. Thus
       ifplugd enables the interface before querying the link status.
       This may be switched off with -a flag. You might want to use it if
       you have a sane network driver (e.g. eepro100). The subdirectory
       patches/ in the ifplugd distribution includes a patch for the
       8139too 0.9.26 driver, which makes the driver compatible with -a.
       Don't ask me how to apply this patch. If you don't know, you won't
       need it.
    4. Q: Does it work with anything else than plain ethernet or wireless
       LAN?
       A: Certainly not, since the MII and ETHTOOL ioctl()s and the
       wireless extension don't exist on other network device types.
    5. Q: I have a Realtek 8139 based network card. Everytime ifplugd
       starts on bootup my machine freezes. What can I do?
       A: This is a bug in the 8139too driver 0.9.25 (at least) shipped
       with Linux 2.4.19, please upgrade to 8139too 0.9.26 (Linux 2.4.20
       or seperately at
       [33]http://www.sourceforge.net/projects/gkernel/).
    6. Q: There are already laptop-net's ifd and miid, why did you write
       your own daemon?
       A: laptop-net was too integrated with its profile system and
       didn't work on my hardware when I had a look on it. It seemed
       easier to me to write a simple but feature complete replacement
       than using laptop-net without most of the special features
       disabled. I didn't know about miid when I wrote ifplugd, but in
       any case ifplugd is much better than miid. For a comparison of
       miid and ifplugd, have a look on
       [34]http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=162763&repeat
       merged=yes
    7. Q: I have two interfaces (e.g. WLAN and copper ethernet), both
       controlled by ifplugd, and want to force the network traffic to go
       over the faster one of them, in case both are available at the
       same time. How can I do this?
       A: A tool I wrote called [35]ifmetric might be exactly what you're
       looking for.

    Lennart Poettering <mzvscyhtq (at) 0pointer (dot) de>, June 2005

   $Id: README.html.in 124 2005-06-04 19:22:59Z lennart $

References

  33. http://www.sourceforge.net/projects/gkernel/
  34. http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=162763&repeatmerged=yes
  35. http://0pointer.de/lennart/projects/ifmetric/
