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<a href="mailto:rgrimsha@syr.edu"></a></font></div>
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<div style="direction: ltr;" id="divRpF23301"><font color="#000000" face="Tahoma" size="2"><b>From:</b> dhcp-users-bounces+rgrimsha=syr.edu@lists.isc.org [dhcp-users-bounces+rgrimsha=syr.edu@lists.isc.org] on behalf of Adam Moffett [adamlists@plexicomm.net]<br>
<b>Sent:</b> Wednesday, September 26, 2012 1:00 PM<br>
<b>To:</b> Users of ISC DHCP<br>
<b>Subject:</b> Re: a couple of match questions<br>
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2) Is it possible to match the <i>lack</i> of option 82 information?<br>
eg: <br>
class "foo" {<br>
match if ((<i>some condition</i>) and (option agent.circuit-id=NULL));<br>
...<br>
}<br>
</blockquote>
On a more general note, would it be possible to make a class(A) on your "some condition" and a class(B) on the agent.circuit-id?<br>
The question is then: can you use a more elaborate allow/deny scheme in the pools?<br>
<br>
All coming down to:<br>
deny B<br>
allow A<br>
<br>
I know this is complicated as the allow/deny rules are not immediately intuitive.<br>
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>>Maybe. Is there some big gotchya with allow/deny that makes it unintuitive? The man page sounds >>straightforward, but now you've got me worried.<br>
<br>
One example is that it is written to be exclusive when allow is used - implicitly denying other matches... yet if you are steering users between transitional groups such as a registration portal, you do need to deny those groups or the server will happily continue
renewing them. Thus it is important to architect a design and test it before promising anything to management.<br>
<br>
Randall Grimshaw<br>
<br>
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