Syslinux - Mar 2010 - Availability of a variable of the TFTP server IP address to be used in pxelinux.cfg/default

Hello,
I'm new to Linux and quite inexperienced - sorry.

I set up about 20 PXE servers with several tools as different boot
images.
Two of the tools require files to be loaded from the TFTP after the
kernel has loaded.

Currently I do the following in pxelinux.cfg/default:

label abc
  kernel def
  append TFTP://2.3.4.5/xyz

My PXE boot images are set on one master server and from there
automatically replicated to all remote PXE/TFTP servers.
For the two images where I have to load files from the TFTP server I
have to set the IP address (2.3.4.5 in the example above) for every
server manually and I have to copy all the images for each server
manually because all my 20 PXE/TFTP servers have different IP addresses.

Now the question:
pxelinux knows the address of the current TFTP server.
Is there a variable/placeholder that can be used in pxelinux.cfg/default
that will automatically pass the current TFTP server address to the
booted Linux OS so I can use ONE image for all my servers?

For the example above I would like to replace the 2.3.4.5 with a
variable.
label abc
  kernel def
  append TFTP://[iAmTheIpAddressOfTheTftpServer]/xyz

Is that possible? Is there something predefined in pxelinux.0?


Thanks,
Michael

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Good day Michael,

In regards to your question about passing the boot server's IP along to
the kernel:

You can get something close.  Take a look at syslinux/doc/syslinux.txt.
Search for the "IPAPPEND" directive.  While it doesn't exactly
match the
format you show on your APPEND lines, perhaps you can process what
IPAPPEND gives you and make it work for you.

- Shao Miller