[syslinux] How to add option dhcp-class-identifier "PXEClient"; with ISH DHCPD v3

[Gerhard Zuber]

hi, a little question regarding pxe-stuff.

I need the boot menu known from Intel PXE PDK so I need to
run pxe service on redhat 8.0 with dhcpd 3

I run pxe and dhcpd on the same server. So the dhcpd server should
give an extra parameter to pxe-clients.

On Redhat 7.3 with dhcpd v2 this was done with the option:

   option dhcp-class-identifier "PXEClient";

On dhcpd v3 this option is rejected !

How do I get around this?

many thanx
Gerhard