Groups and Dynamic Updates SOLVED!

Martin McCormick martin at
Tue Mar 13 02:25:46 UTC 2007

"David W. Hankins" writes and quotes one of my earlier messages:
> On Tue, Feb 27, 2007 at 11:13:32AM -0600, Martin McCormick wrote:
> >       The question I asked earlier today about being able to
> > use the mid-level domain name as a key to assigning hosts to
> > groups is about all that is left.
> Groups maybe not, but classes, I don't see why it couldn't be
> done (with clever use of suffix() and/or substring()). *
> If there were a largeish number of mid-level domains, and it
> were possible to use a single dhcpd.conf syntax to extract
> all the names, I'd also look into subclasses (so the lookup is
> done once on the class linear list, and once on the subclass hash
> table, rather than n-times on the class linear list).
> * - If you're mixing host record contents with class statements,
>   there may be 'chicken and egg' problems.  I think class
>   statements are matched very early on in a client's lifecycle,
>   long before a host record match is given ("least astonishment"
>   bug we haven't fixed yet).

	Thanks again for the excellent discussion.  It turns
out, I honestly panicked because I had no idea how we were going
to support the literally hundreds of PXE clients that presently
are sitting in groups.  There are several departments here who
have rembo servers which manage strings of clients which are on
multiple subnets and even worse, some subnets have PXE clients
from different departments.  All of them send the same
identifier string so how were we going to keep them from getting
each other's options?

	The man page for dhcpd says that groups can be created
and destroyed dynamically via omapi and, unlike groups created
in dhcpd.conf, these groups have names or "group handles" that
tie static hosts to them.  That's what I missed the first time
through.  That, folks, is the resolution.

	It says a lot about the quality of people on this list
that I did not get one nastygram from anybody along the lines of
"You idiot, can't you read the manual?"  Sometimes it takes
multiple readings before things start to sink in.

Martin McCormick WB5AGZ  Stillwater, OK 
Systems Engineer
OSU Information Technology Department Network Operations Group

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