Problems using class match by user-option

Sven Schumacher schumacher at
Thu Dec 7 08:49:33 UTC 2017


I have the following problem: two many clients within a limited range of
I would like to sort the clients which get dynamically their IP in two
pools. One of them is for PXE-Clients or Clients with "official"
ip-adresses, the other one for "nat"-able Clients. But only
"known-clients" shall be assigned an address (later on there might be
the option to assign unknown-clients a third range within a third pool
with no internet-access and in an isolated ip-range, which gets blocked
by firewall on all other devices). So I tried the following in dhcpd.conf:

option tfd-scope-identifier code 230 = text;

class "gaeste" {
  match if (config-option tfd-scope-identifier = "gaeste");

shared-network tfd {

    subnet netmask {
      deny unknown-clients;
    subnet netmask {
      deny unknown-clients;

     host test1 {
         hardware ethernet aa:bb:cc:dd:ee:ff;
         option tfd-scope-identifier "gaeste";
     host test2 {
         hardware ethernet bb:cc:dd:ee:ff:aa;
      pool { # host test2 should get IP of this pool
          deny members of "gaeste";
      pool { # host test1 should get IP of this pool, but didn't
          option routers;
          allow members of "gaeste";

But when I did this, test2 still got an IP of the address range to So the class-match for the config-option
seems to be wrong.
Looking at my syslog only DHCPDISOVER, DHCPREQEST and DHCPACK Messages
are logged.
Is there any way to "debug" the class-match like more verbose output?

Thanks in advance


Sven Schumacher - Systemadministrator Tel: (0511)762-2753
Leibniz Universitaet Hannover
Institut für Turbomaschinen und Fluid-Dynamik       - TFD
Appelstraße 9 - 30167 Hannover
Institut für Kraftwerkstechnik und Wärmeübertragung - IKW
Callinstraße 36 - 30167 Hannover

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