-- MikeGore - 13 Feb 2008

Udev

Notes on using and understanding Udev

External References

• Writing Udev Rules
• Udev FAQ

Usefull commands

• udevinfo - list all of the KERNELS,SUBSYSTEMS,DRIVERS and ATTRS for a device
  • Example udevinfo -a -p /sys/class/net/eth1
• udevtest - test what actions will be done for a device
  • Example udevtest /sys/class/net/eth1

Networking

Notes: Udev Rules replace the /etc/iftab method of matching MAC addresses to device names. (Udev used to read /etc/iftab and make a matching Udev rule set). Now Udev just skips the extra /etc/iftab file and directly matches MAC's

• ifconfig -a - list all network devices detected on your system
• Files located under /etc/udev/rules.d
  • 70-persistent-net.rules - assign network cards to device names - Note CASE MATTERS when matching a MAC - use udevinfo!
    • Note if you are having problems detecting your networks then deleted the contents of this file and reboot - it is automattically generated
  • 75-persistent-net-generator.rules - detect new or changed network cards and update 70-persistent-net.rules
  • 85-ifupdown.rules - bring up or down network devices marked auto
  • 90-modprobe.rules - load network modules if needed