How to ignore a set of Mac addresses in dhcpd.conf?

Question

Is it possible in dhcpd.conf to ignore requests from a set of MAC addresses?

Something like this:

host vminstances {
    hardware ethernet d0:0d:*;
    ignore booting;
}

Answer 1

You can use something like:

class "ignored" {
        match if substring(hardware,1,4) = 00:02;
}


pool {
        deny members of "ignored";
        range 192.168.172.100 192.168.172.149;
        }

Answer 2

From this thread on the mailing list, another option to block specific hosts is:

class "black-hole" {
    match substring (hardware, 1, 6);
    # deny booting;
    ignore booting;
}
subclass "black-hole" <MAC-ADDRESS-TO_IGNORE>;

The thread also says that the difference between ignore and deny is that the later logs the request whereas the former does not.

Answer 3

Why not use the actual feature designed to do this, add the follow to your subnet section for the given network segment:

subnet 192.168.0.0 netmask 255.255.255.0 { deny unknown-clients; }