SV: lease limits, classes & subclasses

[G. Coles]

Hello Lars,

first of all thanks for your reply - very helpful indeed and you gave me new 
insights to try out :) Yes you assumed right the RID is a normal MAC 
address.

Meanwhile I was trying out some things & what I assumed before I started is 
that dhcpd parses the conf file sequentially - so i thought... if I defined 
the classes of those special (but few) RIDs for which I want multiple lease 
limits first then define a normal class that limits all the rest with lease 
limit 1 then I should work.

so i went about defining the classes as follows:

class "limited-to-2-lease" {
             match if substring (option agent.remote-id , 0, 17);
             lease limit 2;
}
subclass "limited-to-1-lease" "XX:XX:XX:XX:XX:XX";
subclass "limited-to-1-lease" "YY:YY:YY:YY:YY:YY";

class "limited-to-1-lease" {
             spawn with option agent.remote-id
             lease limit 1;
}

In fact when I tested it out dhcpd parses conf file sequentially so it 
worked for me
What do you think? is there some caveat somewhere for which I should 
consider defining each and every RID for which I want a lease limit of 1 or 
does my method always work?

What I'm trying to do, I'm sure you noticed this, is that I'm trying to 
avoid defining each and every RID which I want to have a lease limit 1 
because of the huge number (thousands) of MACs that will need to be listed 
here.

Thanks for your link too Lars - extremely helpful

GC

>From: "Lars Jacobsen" <lars-jacobsen at newmail.dk>
>Reply-To: dhcp-users at isc.org
>To: <dhcp-users at isc.org>
>Subject: SV: lease limits, classes & subclasses
>Date: Thu, 15 Mar 2007 20:55:41 +0100
>
> > G. Coles wrote:
> >
> > what i'm trying to do (hopefully this can be done) is to classify dhcp
> > clients into 2 types: example:
> > 1st type: takes 'lease limit 1;'
> > 2nd type: takes 'lease limit 4;'
> >
> > now the only thing I can use in my scenario to classify clients is the
> > option agent.remote-id
> >
>
>Ok how is the struckture af the RID ?
>To me it looks like you are using MAC addresses.
>
>If they are all random then I guess you have to add them one by one,
>something like this:
>
>
>class "limmited-to-1-lease" {
>             match if substring (option agent.remote-id , 0, 17);
>             lease limit 1;
>         }
>         subclass "limmited-to-1-lease" "XX:XX:XX:XX:XX:XX;
>         subclass "limmited-to-1-lease" "YY:YY:YY:YY:YY:YY";
>
>
>class "limmited-to-2-lease" {
>             match if substring (option agent.remote-id , 0, 17);
>             lease limit 2;
>         }
>         subclass "limmited-to-2-lease" "ZZ:ZZ:ZZ:ZZ:ZZ:ZZ;
>
>
>class "limmited-to-4-lease" {
>             match if substring (option agent.remote-id , 0, 17);
>             lease limit 4;
>         }
>         subclass "limmited-to-4-lease" "AA:AA:AA:AA:AA:AA;
>         subclass "limmited-to-4-lease" "BB:BB:BB:BB:BB:BB;
>         subclass "limmited-to-4-lease" "CC:CC:CC:CC:CC:CC;
>
>
>
>Othervice if all the RID´s have something in common like the first 3 bytes
>you can do a match on just that part instead of the whole RID to match a
>class and then use spawning to make a unique class for each RID.
>
>
>class "XX:XX:XX" {
>match if  substring ( (option agent.remote-id) , 0,8)= "XX:XX:XX";
>spawn with option agent.remote-id;
>lease limit 4;
>}
>
>
>class "ZZ:ZZ:ZZ:01-to-ZZ:ZZ:ZZ:02" {
>match if  substring ( (option agent.remote-id) , 0,8)= "ZZ:ZZ:ZZ" AND
>(substring ( (option agent.remote-id) , 8,2)= "01" OR
>substring ( (option agent.remote-id) , 8,2)= "02");
>spawn with option agent.remote-id;
>lease limit 1;
>}
>
>
>class "AA:BB:CC:01-to-AA:BB:CC:04" {
>match if  substring ( (option agent.remote-id) , 0,8)= "AA:BB:CC" AND
>(substring ( (option agent.remote-id) , 8,2)= "01" OR
>substring ( (option agent.remote-id) , 8,2)= "02"
>substring ( (option agent.remote-id) , 8,2)= "03"
>substring ( (option agent.remote-id) , 8,2)= "04");
>spawn with option agent.remote-id;
>lease limit 2;
>}
>
>
>
>I made a little description on my own problems and how I solved them.
>You can find it here:
>www.strammelse.dk/dhcp
>
>
>Regards
>
>/Lars
>
>

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