dhcpd and interface name

Valeri Galtsev galtsev at kicp.uchicago.edu
Mon Aug 15 14:30:43 UTC 2016

On Mon, August 15, 2016 8:06 am, Ernie Luzar wrote:
> Alnis Morics wrote:
>> On 08/15/2016 02:58 PM, Ernie Luzar wrote:
>>> When starting dhcpd at boot time the rc.conf contains dhcpd_iface"rl0"
>>>  but when restarting using /usr/local/etc/rc.d/isc-dhcpd restart all
>>> interfaces on the host get included.
>>> Is there a dhcpd.conf statement for defining the interface to use?
>> Did you quote it exactly how you have it it rc.conf? The syntax should
>> be:
>> dhcpd_enable="YES"
>> dhcpd_ifaces="rl0"
>> -Alnis
> Let me restate to make more clear.
> When starting dhcpd at boot time the rc.conf contains dhcpd_iface="rl0"
> and dhcp is limited to the rl0 interface as desired.
> But when restarting using "/usr/local/etc/rc.d/isc-dhcpd restart"
> command, all interfaces on the host get included, not just rl0.

The following is not a solution, just an observation. If all of your
"other" interfaces are outside the IP ranges configured in DHCP server
configuration, then upon restart DHCP server will still ignore them and
will not respond to any DHCP requests coming to these interfaces. This is
as far as I remember how ISC DHCP server works (am I outdated?).

So, I've got the following questions: do any of your other interfaces fall
inside one of your DHCP ranges? Please, show all

        range dynamic-bootp  x.x.x.x y.y.y.y;

lines from your /usr/local/etc/dhcpd.conf file; and give list of all IP
addresses your network interfaces have. Do you indeed observe on the
interface outside your "range dynamic-bootp " responses from your ISC DHCP
server to DHCP requests? If yes, this will be fair grounds for bug report


> This is because the statements in rc.conf are not being reread when
> using this restart command systax.
> So I am thinking there must be some way to code the interface name in
> the dhcpd.conf itself. I read the man pages and could not find anything
> along this line.
> So I am asking here, is there a dhcpd.conf statement for defining the
> interface to use? If so, what is it?

Valeri Galtsev
Sr System Administrator
Department of Astronomy and Astrophysics
Kavli Institute for Cosmological Physics
University of Chicago
Phone: 773-702-4247

More information about the freebsd-questions mailing list