docker-dhcp-server/isc-dhcp/dhcpd.conf

ddns-update-style none;

option classless-routes code 121 = array of unsigned integer 8;
option classless-routes-win code 249 = array of unsigned integer 8;

default-lease-time 600;
max-lease-time 7200;

use-host-decl-names on;

authoritative;

log-facility local7;

subnet 10.15.100.0 netmask 255.255.255.0 {

  range 10.15.100.50 10.15.100.250;
  option subnet-mask 255.255.255.0;
  option broadcast-address 10.15.100.255;
  option routers 10.15.100.1;

  option domain-name "site.rthoni.com";
  option domain-name-servers 10.15.100.1;

  #option classless-routes 24, 10,15,42, 10.15.12,2;
  #option classless-routes-win 24, 10,15,42, 10.15.12,2;

  next-server 10.15.100.1;
  if exists user-class and ( option user-class = "iPXE-rthoni" ) {
    filename "http://netboot/boot.ipxe";
  }
  else {
    filename "ipxe-rthoni.kpxe";
  }
#  option root-path "10.15.100.1:/pxeroot/ubuntu";

}