PXE tftp file precedence

Order

Next, it will search for the config file using its own IP address in upper case hexadecimal, e.g. 192.0.2.91 -> C000025B (you can use the included progam gethostip to compute the hexadecimal IP address for any host). If that file is not found, it will remove one hex digit and try again. Ultimately, it will try looking for a file named default (in lower case). As an example, if the boot file name is /mybootdir/pxelinux.0, the Ethernet MAC address is `88:99:AA:BB:CC:DD` and the IP address 192.0.2.91, it will try following files (in that order):

       /mybootdir/pxelinux.cfg/01-88-99-aa-bb-cc-dd
       /mybootdir/pxelinux.cfg/C000025B
       /mybootdir/pxelinux.cfg/C000025
       /mybootdir/pxelinux.cfg/C00002
       /mybootdir/pxelinux.cfg/C0000
       /mybootdir/pxelinux.cfg/C000
       /mybootdir/pxelinux.cfg/C00
       /mybootdir/pxelinux.cfg/C0
       /mybootdir/pxelinux.cfg/C
       /mybootdir/pxelinux.cfg/default

HEX Converter

printf '%02X' ${IP_ADDR//./ }

References

• http://www.syslinux.org/wiki/index.php/PXELINUX