Garbage collection?

David W. Hankins dhankins at
Thu Sep 10 18:05:00 UTC 2009

On Thu, Sep 10, 2009 at 11:37:13AM -0500, Peter Laws wrote:
> And if Apple used a specific OUI range for iPhones/iPod Touches, we would 
> happily do that (how does that "deny" keyword work again??? :-). 
> Unfortunately, that doesn't seem to be the case.  If anyone knows 
> different, please, speak up!!

if the client sends a vendor-class-identifier (i don't know, i don't
have an iphone), or even a default client-hostname or something, it is

if a client doesn't send a vendor-class-id it gets hard.  but you can
often fingerprint a client by the dhcp-parameter-request-list the
client sends.  lots of clients request the same options, but you can
tell clients apart by the distinct order they put the options in.

unfortunately there's some overlap...

if you google 'dhcp fingerprinting' it will probably find some other
bits of email from this list, ages ago, with example configs.

David W. Hankins	"If you don't do it right the first time,
Software Engineer		     you'll just have to do it again."
Internet Systems Consortium, Inc.		-- Jack T. Hankins
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