pfSense

One use case is for pxelinux with options 208,209,210.
The client will not request these options so it must be forced to do so.

It appears that "append dhcp-parameter-request-list" does not work as expected and apparently only sends the numbers listed.
I have found mention to "option dhcp-parameter-request-list = concat(option dhcp-parameter-request-list,d0,d1,d2,d3);" working.
I haven't be able to test it yet.

The required process would involve editing
/usr/local/www/services_dhcp.php
on 2.2.3-RELEASE
changes should be made around line 1134

/etc/inc/services.inc
on 2.2.3-RELEASE
the required changes should be made somewhere around lines 822 - 832 if append will work
else around lines 858 maybe for the concat option one?

Hopefully this can be of help.