DHCP code in 2.0.4+

Martin Lorentz ml at goetel.net
Fri Jun 5 18:02:39 CEST 2009

Hello everyone from a long-time user of freeradius, but this is my first
post on the list.

While playing around with the experimental DHCP code in the latest
freeradius releases, I came across a problem where the DHCP packet is
not recognized, when the Message-Type is not the first among the list of
options. Currently, the code uses a static offset to look for the
message type in the packet. A patch is enclosed to fix the problem by
iterating through the available options, but will most likely need
fixing by someone who knows how to code :-) It applies to 2.0.6 and
works in the lab, though.

Also, I'm interested to hear about the plans for DHCP in freeradius.
Personally, I'm evaluating a solution to assign static IPs based on the
Agent-Circuit-Id without being tied to a specific MAC - something ISC
dhcpd will not do by design. This is supposed to eventually replace
PPPoE connections from CPEs. I guess freeradius could someday be able to
handle this since the backend data store is really flexible. While most
users will probably use the DHCP code with a leases database, in our
scenario the configuration would just hand out a static IP calculated
from the values in the Agent-Circuit-ID, probably by making use of

Another suggestion with regards to the server design. Currently, the
whole server needs to run as root to bind to port 67. That's not
necessary for a RADIUS server binding only to ports above 1024. For the
long run, would it be feasible to separate the DHCP server code into its
own daemon, as a pure DHCP-to-RADIUS translator?

Best regards,

Martin Lorentz

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