DHCPINFORM via a relay agent

David W. Hankins David_Hankins at isc.org
Sun Aug 20 15:47:13 UTC 2006

On Sat, Aug 19, 2006 at 07:59:30PM +0900, Kan Sasaki wrote:
> I'm confused. Which is wrong? Is this a bug or a configuration issue?

This is a compounded bug.  Existing code that attempted to work with
clients that specify a ciaddr of was 'enhanced' to deal even
better with them.  In the meantime, we appear to have brkoen clients
that specify non-zero ciaddr via relays.

You will have noted from your careful reading of rfc already that
such zero-ciaddr-DHCPINFORM clients are already not implementing

I would hope that a future version of ISC DHCP would remove this
zero-ciaddr-client-handling behaviour by default, and move it to
a configuration option, with the minor change regarding using
the relay (should only use the relay when ciaddr is zero, and
always set the broadcast flag).

We can probably change the relay behaviour in 3.0.5rc2, but we'll
have to do the configurable option bits in 3.1.0 or later.

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David W. Hankins	"If you don't do it right the first time,
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