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iPXE get custom dhcp option (option nisplus-domain string) - Printable Version

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iPXE get custom dhcp option (option nisplus-domain string) - Torgeir - 2012-09-17 14:19

Hi!

Is it possible to get out a custom dhcp option "option nisplus-domain string" from within iPXE?

Or easily done by adding to source and build from source?
Dont know how all this is tied together...

Regards,
Torgeir

RE: iPXE get custom dhcp option (option nisplus-domain string) - mcb30 - 2012-09-17 16:00

(2012-09-17 14:19)Torgeir Wrote:  Is it possible to get out a custom dhcp option "option nisplus-domain string" from within iPXE?

You should be able to access the NIS+ domain using:

Code:
echo ${64:string}

You'll need to force your DHCP server to hand out this option even though iPXE doesn't request it. With ISC dhcpd, you can do this using something like:

Code:
append dhcp-parameter-request-list 64;

in /etc/dhcpd.conf.

Michael

RE: iPXE get custom dhcp option (option nisplus-domain string) - Torgeir - 2012-09-17 16:11

Cool, thanks Smile

I know.

Here we have used the NIS+ domain string for something that would be useful for us to get out in a iPXE boot environment.

Torgeir

RE: iPXE get custom dhcp option (option nisplus-domain string) - mcb30 - 2012-09-17 16:14

(2012-09-17 16:11)Torgeir Wrote:  But here we have used the NIS+ string for something that would be cool to be able to get out in iPXE.

I don't understand what you're saying, sorry.

You can access the DHCP option via ${64:string}, and embed that in whatever command you like. If you want to use it as a web server address, for example, you can do something like

Code:
kernel http://${64:string}/boot.ipxe

What are you trying to do with the NIS+ server option, and what is the problem you are having?

Michael

RE: iPXE get custom dhcp option (option nisplus-domain string) - Torgeir - 2012-09-17 16:39

It worked! Smile

Added to (dhcpd.conf)
append dhcp-parameter-request-list 64;

inside my scope
option nisplus-domain "somehing_useful";

Torgeir
(2012-09-17 16:14)mcb30 Wrote:  
(2012-09-17 16:11)Torgeir Wrote:  But here we have used the NIS+ string for something that would be cool to be able to get out in iPXE.

I don't understand what you're saying, sorry.

You can access the DHCP option via ${64:string}, and embed that in whatever command you like. If you want to use it as a web server address, for example, you can do something like

Code:
kernel http://${64:string}/boot.ipxe

What are you trying to do with the NIS+ server option, and what is the problem you are having?

Michael

Sorry! I was unclear.

We have a string inside the "option nisplus-domain string" that we want to add to our kickstart installer (as boot argument). So we can pick it up with cat /proc/cmdline, and then use that information by our post/pre kickstart scripts.

Torgeir